North Korea's Nuclear Weapons Development and Diplomacy
Prepared for Members and Committees of Congress
In 1994, an Agreed Framework was negotiated between the Clinton Administration and North
Korea, specifying measures to limit and eventually eliminate North Korea’s nuclear programs. In
late 2002, the Agreed Framework broke down over U.S. evidence that North Korea was operating
a secret nuclear program. North Korea restarted nuclear installations that had been frozen under
the Agreed Framework. Negotiations ensued in 2003 involving six governments: the United
States, North Korea, China, South Korea, Japan, and Russia.
The six parties to the North Korean nuclear negotiations concluded an agreement on February 13,
2007, that specifies two phases of implementation. The phases provided for a freeze of North
Korean nuclear installations at the Yongbyon site, a subsequent disablement of all North Korean
nuclear facilities, and a North Korean declaration of “all nuclear programs.” The Six Party
Agreement was negotiated following a North Korean nuclear test in October 2006. The nuclear
test signaled progress by North Korea in reprocessing plutonium since 2002 for six to eight
atomic bombs. The agreement also came about because of changes in Bush Administration policy.
Tactically, the Administration ended its unwillingness to negotiate bilaterally with North Korea
and actively sought bilateral meetings; the details of the Agreement were negotiated at these
The Bush Administration negotiated three subsequent agreements with North Korea. They
produced the initiation of a disablement of North Korean nuclear installations at Yongbyon, inside
North Korea, including a nuclear reactor and plutonium reprocessing plant; Bush Administration
lifting of Trading With the Enemy Act sanctions against North Korea and removal of North Korea
from the U.S. list of state sponsors of terrorism; and a North Korean declaration of nuclear
programs limited to known nuclear installations at Yongbyon and reportedly a plutonium
stockpile of 30 kilograms. The third of these agreements, negotiated in October 2008, established
a system of verification and inspections but limited to the declared facilities at Yongbyon and not
including the taking of samples by inspectors. At a six party meeting in December 2008, the Bush
Administration failed to get North Korea to agree to include sampling in a written agreement.
These agreements did not cover important components of North Korea’s nuclear programs: the
apparent production of a few atomic bombs; a highly enriched uranium program known to the
United States since the late 1990s; and alleged nuclear collaboration with Iran and Syria.
According to U.S. officials, collaboration with Syria involved the construction of a nuclear
reactor, which Israel bombed in September 2007. Collaboration with Iran reportedly involves
development of high enriched uranium, development of a nuclear warhead that could be mounted
on a jointly developed intermediate range ballistic missile (North Korean Nodong, Iranian Shahab
missile), and North Korean assistance in constructing deep underground installations to house
part of Iran’s nuclear program.
This report will be updated periodically.
U.S.-North Korea Nuclear Agreement............................................................................................1
The Implementation Process.....................................................................................................3
North Korea’s Nuclear Programs....................................................................................................5
Highly Enriched Uranium (HEU) Program..............................................................................6
Nuclear Collaboration with Iran and Syria...............................................................................7
North Korea’s Delivery Systems..............................................................................................11
State of Nuclear Weapons Development.................................................................................12
For Additional Reading.................................................................................................................15
Author Contact Information..........................................................................................................15
In December 2008, the Bush Administration failed to secure North Korean agreement for the
issuance of a statement by the governments of the six party negotiations on North Korean nuclear
programs. North Korea rejected U.S. proposals that the statement include a provision that would
allow six party inspectors to take samples of nuclear materials from North Korea’s declared
nuclear facilities. The failure to resolve this dispute over a verification system, especially the right
of inspectors to take samples, cast into doubt the completion of implementation of a U.S.-North 1
Korean nuclear agreement that had been negotiated in stages since January 2007.
On June 26, 2008, the North Korean government and the Bush Administration took measures to
implement a nuclear agreement that they had negotiated in 2007 into 2008. The details of the
agreement were finalized details in April 2008 at a meeting of the chief U.S. and North Korean 2
negotiators in Singapore. The agreement, if fully implemented, would complete the second phase
of an accord reached by the six party conference on North Korean nuclear issues in February
2007 and detailed more fully in a six party statement of October 2007. (The six parties are the
United States, China, North Korea, South Korea, Russia, and Japan).
The agreement created two obligations each for North Korea and the Bush Administration to
fulfill. North Korea is to allow a process of disablement of its plutonium nuclear facilities at
Yongbyon, a site 60 miles from the capital of Pyongyang. The shutting down of Yongbyon was a
key provision of the 1994 Agreed Framework negotiated by the Clinton Administration and North
Korea. Yongbyon ceased to operate between 1994 and the end of 2002. In late 2002, the Bush
Administration suspended U.S. obligations under the Agreed Framework because of U.S.
intelligence estimates that North Korea was operating a secret nuclear weapons program based on
highly enriched uranium. North Korea responded by re-starting the Yongbyon facilities. Between
early 2003 and the summer of 2007, the Yongbyon reactor and the plutonium reprocessing plant
produced enough weapons grade plutonium for the production of several atomic bombs. North
Korea tested an atomic device in October 2006.
The disablement process began in October 2007. The Bush Administration said in June 2008 that
eight of eleven components of the disablement process have been completed and that close to
removed. Administration officials have stated that a completed disablement of the Yongbyon
installations would be extensive enough so that it would take North Korea about a year to re-start 4
them, but subsequent developments indicated that North Korea could restart the plutonium
reprocessing plant within three to four months.
North Korea’s second obligation was to provide the United States and other members of the six
party talks with a “complete and correct” declaration of nuclear programs. The declaration
1 Glenn Kessler, “N. Korea doesn’t agree to written nuclear pact,” Washington Post, December 12, 2008.
2 “Bush OKs Singapore Agreement: WH [White House],” Yonhap News Agency (Seoul), April 14, 2008. Melanie Lee
and Daryl Loo, “Nuclear talks with N. Korea make progress, US says,” Reuters, April 8, 2008.
3 White House Press Spokesman, Press Fact Sheet: Presidential Action on State Sponsor of Terrorism (SST) and the
Trading with the Enemy Act (TWEA), June 26, 2008.
4 “Restoring disabled N. Korea nukes would need year—US,” Reuters, November 22, 2007.
negotiated and reportedly finalized in Singapore and delivered to China on June 26, 2008,
contains a declaration of the amount of plutonium that North Korea claims to possess. Reports 5
asserted that North Korea declared 30.8 kilograms of plutonium. U.S. intelligence estimates 6
reportedly conclude that North Korea has accumulated 50 to 60 kilograms of plutonium.
However, other components of North Korea’s nuclear programs reportedly are omitted from the
declaration, apparently based on concessions the Bush Administration made to North Korea in the
Singapore agreement. These include the number of atomic bombs North Korea possesses,
information about the facilities where North Korea produces and tests atomic bombs, and the
locations where North Korea stores plutonium and atomic bombs. The declaration also reportedly
contains no information about North Korea’s reported highly enriched uranium program or North
Korea’s reported nuclear collaboration activities with Iran and Syria. According to Bush
Administration officials, the uranium enrichment and Syria issues are addressed in a “confidential 7
minute.” (They have said nothing about Iran.) However, in the confidential minute, North Korea
reportedly does not admit to uranium enrichment or proliferation activities with Syria. It merely 8
“acknowledges” U.S. concerns that North Korea has engaged in these activities in the past.
The United States’ two obligations under the agreement are to remove North Korea from the U.S.
Trading with the Enemy Act and from the U.S. list of state sponsors of terrorism. Removal from
the Trading with the Enemy Act will allow U.S. companies to import North Korean goods and
sell non-strategic goods to North Korea. It opens up possibilities for U.S. companies to invest in
North Korea. However, given North Korea’s communist economic system and its suspicions of
foreign intrusions, there appears to be little likelihood of any meaningful trade or investment 9
relations developing between the United States and North Korea. Removal from the Trading with
the Enemy Act could give North Korea in the future access to $31.7 million in North Korean 10
assets in the United States that have been frozen since the Korean War.
Removal from the U.S. list of state sponsors of terrorism will end the requirement that U.S.
presidents oppose North Korean membership in international financial agencies like the World
Bank and the International Monetary Fund. Because of North Korea’s economic system and
secretive economic activities, its prospects for near term membership in or aid from the World
Bank and the IMF appear to be remote. However, in likely nuclear negotiations in 2009 under the
Obama Administration, it is probable that North Korea will demand that the incoming Obama
Administration “complete” North Korea’s removal from the terrorism support with an
“affirmative act” of initiating proposals for North Korea to receive financial aid from the World
Bank and the International Monetary Fund.
North Korea may have three additional motives for its pressure on the Bush Administration to
remove it from the list of state sponsors of terrorism. One is to reduce U.S. support for Japan on
5 “North Korea tells China 30.8 kg of plutonium extracted,” Agence France Presse, October 24, 2008.
6 Glenn Kessler, “U.S. increases estimate of N.Korean plutonium,” Washington Post, May 14, 2008.
7 Anne Gearan, “U.S. official: North Korea has agreed to intensive US verification of its plutonium production,”
Associated Press, June 26, 2008. Helene Cooper, “Past deals by N.Korea may face less study,” New York Times, April
18, 2008. p. A5.
8 Anne Gearan, “U.S. official: North Korea has agreed to intensive US verification of its plutonium production,”
Associated Press, June 26, 2008.
9 Missy Ryan, “Slim trade impact seen in US move on N.Korea sanctions,” Reuters, June 26, 2008.
10 U.S. Treasury Department, Calendar Year 2006 Fifteenth Annual Report to the Congress on Assets in the United
States of Terrorist Countries and International Terrorism Program Designees, September 2007.
the issue of Japanese citizens kidnapped by North Korea. The Clinton and Bush administrations
previously had cited a resolving of the Japanese kidnapping issue as linked to removal of North
Korea from the terrorism support list. A second motive apparently is to improve the prospects for 11
normalization of diplomatic relations with the United States, which North Korea says it wants.
A possible third motive may be to remove any U.S. incentive to examine the issue of North
Korea’s activities in the Middle East and deny to the United States a potential negotiating lever
over North Korea’s activities in the Middle East. Numerous reports indicate that North Korea’s
activities include providing training and weapons to Hezbollah and cooperation with the Iranian
Revolutionary Guards in the development of both missiles and nuclear weapons. (See subsequent
section on “Nuclear Collaboration with Iran and Syria.” See also CRS Report RL30613, North
Korea: Terrorism List Removal?)
On June 26, 2008, North Korea submitted its declaration of nuclear programs to China, the
chairman of the six party talks. Simultaneously, President Bush announced that he had removed
North Korea from the Trading with the Enemy Act. The President has full authority to renew
annually Trading with the Enemy Act sanctions on North Korea or to lift those sanctions from
President Bush also announced that he had sent to Congress notification of his intent to remove
North Korea from the list of state sponsors of terrorism after 45 calendar days, on August 11,
2008. Under U.S. law, the President is required to notify Congress 45 days before removing a
country from the list. The White House said that North Korea would be removed on August 11, 12
2008, unless Congress acted legislatively to block removal. However, the White House also said
on June 26, 2008, that removal of North Korea was conditioned on North Korean acceptance of
provisions for U.S. verification of the North Korean declaration of nuclear programs.
On June 27, 2008, North Korea blew up the cooling tower of its nuclear reactor at Yongbyon as a
symbol of the continuing disablement process. China, as chairman of the six party talks, called a
six party meeting on July 10-12, 2008. A six party press communique announced that North
Korea had agreed to complete the disablement of Yongbyon by the end of October 2008. Also, by
that date, the United States, China, South Korea and Russia are to complete the provision to
North Korea of one million tons of heavy fuel oil and other forms of energy assistance that had
been promised under the February 2007 six party agreement.
However, the Bush Administration did not remove North Korea from the list of state sponsors of
terrorism on August 11, 2008. In July, the Administration presented North Korea with a draft
protocol on verification of North Korea’s nuclear programs. The draft protocol would have given
U.S. and other six party inspectors the right to conduct inspections at sites throughout North
Korea. North Korea rejected the U.S. proposal, arguing that inspections should cover only those
facilities at Yongbyon that it had listed in its declaration of June 26, 2008. North Korea retaliated
11 “N Korea wants normalized relations with the US,” Dong-A Ilbo (Seoul, internet), June 6, 2008.
12 White House Press Spokesman, Fact Sheet: Presidential Action on State Sponsor of Terrorism (SST) and the Trading
with the Enemy Act (TWEA), June 26, 2008.
by halting the disablement process at Yongbyon and announcing that it would restart the 13
plutonium reprocessing plant at Yongbyon.
Neither the February 2007 nor the October 2007 nuclear agreements (which was put in the form
of a six party statement) mentioned a system of verifying the implementation of the agreements.
There is no evidence that the Singapore agreement of April 2008 detailed any system of
verification. However, following the U.S.-North Korean meeting at Singapore, the Bush
Administration began to seek supplemental agreements with North Korea regarding the
establishment of verification mechanisms to examine North Korea’s declaration of its plutonium
stockpile. In early May 2008, the Bush Administration and North Korea negotiated an accord for
North Korea to turn over to the United States over 18,000 documents related to its plutonium
program, dating back to 1986. U.S. experts currently are examining these documents. The White
House announcement of June 26, 2008, of submission to Congress of notification of intent to
remove North Korea from the terrorism support list stated that removal after 45 days would be
carried out “only after the six parties reach agreement on acceptable verification principles and an
acceptable verification protocol; the six parties have established an acceptable monitoring
mechanism; and verification activities have begun.”
The six party meeting of July 10-12, 2008, reached agreement on verification principles,
including inspection of Yongbyon facilities, review of documents, and interviews of North
Korean nuclear scientists and technicians. Verification would be carried out by experts of the six
parties. The International Atomic Energy Agency would have only an advisory role. However, the
Bush Administration also gave North Korea a draft protocol on verification, which proposed an
inspection system that would have access to any site in North Korea, including military facilities, 14
and to all materials at these sites. North Korea rejected the U.S. proposal. The Bush
Administration decided not to remove North Korea from the terrorism support list on August 11,
2008. North Korea immediately announced a suspension of the disablement of Yongbyon and on
August 26, 2008, an intention to restart the plutonium reprocessing plant.
The Bush Administration reacted to North Korea’s announcement of a restarting of the plutonium
reprocessing by scaling back the scope of its verification proposals. Assistant Secretary of State
Christopher Hill went to Pyongyang in early October and negotiated a verification deal, which 15
would concentrate inspections only on Yongbyon. North Korea agreed and announced a
resumption of disablement. The Bush Administration followed on October 11, 2008, by the
announcement of Secretary of State Condoleezza Rice that North Korea was removed from the
U.S. list of state sponsors of terrorism.
The State Department’s description of the verification agreement included the following points.
Inspectors would have access only to the sites at Yongbyon in North Korea’s June 16, 2008
declaration. Access to non-declared sites would be by “mutual consent.” The inspection
organization would be composed of the five non-North Korean members of the six party talks—
the United States, China, South Korea, Japan, and Russia. The organization would make decisions
13 Glenn Kessler, “Far-reaching U.S. plan impaired N.Korea deal; demands began to undo nuclear accord,” Washington
Post, September 26, 2008, p. A20.
14 Glenn Kessler, “Far-reaching U.S. plan impaired N. Korea deal; demands began to undo nuclear accord,”
Washington Post, September 26, 2008, p. A20.
15 Special briefing by State Department spokesman, Sean McCormack, M2 Presswire, October 11, 2008.
on the basis of unanimous consent. The terms of the verification agreement were contained in a 16
U.S.-North Korean document and in “certain other understandings.”
The Bush Administration and the State Department give few details on two other aspects of Hill’s
talks in Pyongyang and the verification agreement. One was the issue of inspectors being able to
take samples of nuclear materials at the Yongbyon installations for laboratory analysis. A North
Korean Foreign Ministry statement of November 11, 2008, and subsequent statements asserted
that the written verification agreement said nothing about sampling and that North Korea only
had to abide by the written agreement and nothing else. The State Department then acknowledged 17
that Hill’s discussion with North Koreans about sampling was only a verbal understanding. This
issue was not resolved in the December 2008 six party meeting.
The second aspect of Hill’s talks was his meeting with North Korean Lt. General Lee Chan-bok.
This was the first time that a North Korean military leader had participated in the nuclear talks.
General Lee reportedly called for bilateral U.S.-North Korean military talks and may have linked 18
U.S. acceptance of bilateral military talks to further progress on the nuclear issue. Hill and the
State Department have been silent on the content of this meeting, including whether or not Hill
committed the United States to bilateral military talks in the near future.
Most of North Korea’s plutonium-based nuclear installations are located at Yongbyon, 60 miles
from the North Korean capital of Pyongyang. They are the facilities covered by the 1994 U.S.-
North Korean Agreed Framework and by the freeze and disablement provisions in Phases One
and Two of the February 2007 Six Party Nuclear Agreement. The key installations are as 19
• An atomic reactor, with a capacity of about 5 electrical megawatts that began
operating by 1987. It is capable of expending enough reactor fuel to produce
about 6 kilograms of plutonium annually—enough for the manufacture of a
single atomic bomb annually. North Korea in 1989 shut down the reactor or
about 70 days; U.S. intelligence agencies believe that North Korea removed fuel
rods from the reactor at that time for reprocessing into plutonium suitable for
nuclear weapons. In May 1994, North Korea shut down the reactor and removed
about 8,000 fuel rods, which could be reprocessed into enough plutonium (25-30
kilograms) for 4-6 nuclear weapons. North Korea started operating the reactor
again in February 2003, shut it down in April 2005, and said it had removed
another 8,000 fuel rods.
17 “N. Korea rejects contentions it is delaying denuclearization,” Kyodo News, November 12, 2008. “NKorea will not
let nuclear samples out of country,” Reuters, November 12, 2008.
18 ”N. Korea proposes military talks with U.S.,” Kyodo News, October 5, 2008. “Jin Dae-woong: N.K. delivered U.S.
Ultimatum on Nuke Dispute,” Korea Herald (internet), October 7, 2008.
19 Albright, David and O’Neill, Kevin. Solving the North Korean nuclear puzzle. Washington, DC, Institute for Science
and International Security Press, 2000. pp. 57-82.
• Two larger (estimated 50 megawatts and 200 electrical megawatts) reactors under
construction at Yongbyon and Taechon since 1984. According to U.S.
Ambassador Robert Gallucci, these plants, if completed, would be capable of
producing enough spent fuel annually for 200 kilograms of plutonium, sufficient
to manufacture nearly 30 atomic bombs per year. However, when North Korea
re-opened the plutonium program in early 2003, reports indicate that construction
on the larger reactors was not resumed.
• A plutonium reprocessing plant about 600 feet long and several stories high. The
plant would separate weapons grade plutonium-239 from spent nuclear fuel rods
for insertion into the structure of atomic bombs or warheads. U.S. intelligence
agencies reportedly detected North Korean preparations to restart the plutonium
reprocessing plant in February and March 2003. According to press reports, the
CIA estimated in late 2003 that North Korea had reprocessed some of the 8,000
fuel rods. In January 2004, North Korean officials showed a U.S. nuclear expert,
Dr. Sigfried Hecker, samples of what they claimed were plutonium oxalate
powder and plutonium metal. Dr. Hecker later said in testimony before the Senate
Foreign Relations Committee (January 21, 2004) that, without testing, he could
not confirm whether the sample was metallic plutonium “but all observations I
was able to make are consistent with the sample being plutonium metal.” IAEA
monitors in July 2007 stated that the reprocessing plant was not in operation.
Satellite photographs reportedly also show that the five megawatt reactor has no attached power
lines, which it would have if used for electric power generation.
Persons interviewed for this study believe that North Korea developed the five megawatt reactor
and the reprocessing plant with its own resources and technology. It is believed that Kim Jong-il,
the son and successor of President Kim Il-sung who died in July 1994, directs the program, and
that the military and the Ministry of Public Security implement it. North Korea reportedly has
about 3,000 scientists and research personnel devoted to the Yongbyon program. Many have
studied nuclear technology (though not necessarily nuclear weapons production) in the Soviet
Union and China and reportedly Pakistan.
North Korea’s secret highly enriched uranium (HEU) program appears to date from at least 1996.
Hwang Jang-yop, a Communist Party secretary who defected in 1997, has stated that North Korea
and Pakistan agreed in the summer of 1996 to trade North Korean long-range missile technology 20
for Pakistani HEU technology. Other information dates North Korea-Pakistan cooperation to
1993. The Clinton Administration reportedly learned of it in 1998 or 1999, and a Department of
Energy report of 1999 cited evidence of the program. In March 2000, President Clinton notified
Congress that he was waiving certification that “North Korea is not seeking to develop or acquire
the capability to enrich uranium.” The Japanese newspaper Sankei Shimbun reported on June 9,
2000, the contents of a “detailed report” from Chinese government sources on a secret North
Korean uranium enrichment facility inside North Korea’s Mount Chonma. Reportedly, according
20 Kim Min-cheol. “Hwang tells of secret nuke program.” Choson Ilbo (Seoul, internet version), July 5, 2003.
to a CIA report to Congress, North Korea attempted in late 2001 to acquire “centrifuge-related 21
materials in large quantities to support a uranium enrichment program.”
The CIA estimated publicly in November 2002 that North Korea could produce two atomic 22
bombs annually through HEU beginning in 2005; other intelligence estimates reportedly project
a bomb producing capability between 2005 and 2007. Ambassador Robert Gallucci, who
negotiated the 1994 U.S.-North Korean Agreed Framework, and Mitchell Reiss, head of the State
Department’s Policy Planning Bureau until 2004, have stated that a functioning North Korean
HEU infrastructure could produce enough HEU for “two or more nuclear weapons per year.” The
Washington Post of April 28, 2004, quoted an U.S. intelligence official saying that a North
Korean HEU infrastructure could produce as many as six atomic bombs annually. Administration
officials have stated that they do not know the locations of North Korea’s uranium enrichment
program or whether North Korea has assembled the infrastructure to produce uranium-based 23
Knowledgeable individuals believe that the Soviet Union did not assist directly in the
development of Yongbyon in the 1980s. The U.S.S.R. provided North Korea with a small
research reactor in the 1960s, which also is at Yongbyon. However, North Korean nuclear
scientists continued to receive training in the U.S.S.R. up to the demise of the Soviet Union in
December 1991. East German and Russian nuclear and missile scientists reportedly were in North
Korea throughout the 1990s. Since 1999, reports have appeared that U.S. intelligence agencies
had information that Chinese enterprises were supplying important components and raw materials 24
for North Korea’s missile program.
In April 2008, the Bush Administration disclosed that a facility at Al Kibar in northeast Syria
bombed by Israel on September 6, 2007, was a plutonium nuclear reactor under construction with
the apparent aim of producing nuclear fuel rods that could be converted into nuclear weapons-
grade plutonium. For months after the Israeli bombing, press reports had cited information and
evidence that the facility was a nuclear reactor and that North Korea was assisting Syria in its 25
construction. This nuclear collaboration reportedly was ongoing since 1997. U.S. intelligence
officials on April 24, 2008, privately briefed Members of Congress on North Korea’s role, and 26
they provided a background news briefing to the media. (See CRS Report RL33487, Syria:
Background and U.S. Relations.)
21 Pincus, Walter. “N. Korea’s nuclear plans were no secret.” Washington Post, February 1, 2003. p. A1.
22 CIA unclassified point paper distributed to Congress, November 19, 2002.
23 Kessler, Glenn. “New doubts on nuclear efforts by North Korea.” Washington Post, March 1, 2007. p. A1.
24 “ROK source views CIA report on DPRK production of plutonium.” Chungang Ilbo (internet version), February 25,
2001. Gertz, Bill. “Pyongyang’s launch met by indifference.” Washington Times, May 16, 1999. p. C1.
25 Sara A. Carter and Bill Gertz, “Intelligence on Syria delayed to avoid fight,” Washington Times, April 25, 2008, p.
26 David E. Sanger, “Bush Administration released images to bolster its claims about Syrian reactor,” New York Times,
April 25, 2008, p. A1.
U.S. officials presented several forms of evidence for North Korean involvement in the Syrian
reactor. A U.S. photograph showed a top North Korean nuclear official visiting Syrian nuclear
experts. U.S. intelligence officials released photographs of the outside and inside of the reactor
showing marked similarities with the North Korean nuclear reactor at Yongbyon. The photos of 27
the interior of the reactor reportedly showed North Koreans inside the reactor. A leading South
Korean newspaper had reported that U.S. intelligence agencies had obtained a list of North
Korean officials involved in the Syrian reactor project and that chief U.S. negotiator, Christopher 28
Hill, had confronted North Korean nuclear negotiators with the list.
At the time of the Bush Administration’s disclosures, South Korean intelligence officials stated 29
that they had information that the Israeli bombing had killed ten North Koreans.
U.S. officials said that the Al Kibar reactor was nearly operational at the time of the Israeli
bombing. However, non-government nuclear experts questioned that assertion, asserting that
there was no evidence of a plutonium reprocessing plant and a facility to produce nuclear fuel for 30
the reactor in Syria.
One potential answer to the question of the absence of other reactor-related plutonium facilities in
Syria came in reports later in 2008 that Iran also was involved in the Syrian reactor with North
Korea and that a plutonium reprocessing plant was in Iran. The online service of the German
news publication Der Spiegel cited “intelligence reports seen by Der Spiegel” that North Korean
and Iranian scientists were working together at the reactor site at the time of the Israeli bombing.
Some of the plutonium fuel rod production from the reactor was to have gone to Iran, which
viewed the reactor as a “reserve site” to produce weapons-grade plutonium as a supplement to 31
Iran’s own highly enriched uranium program. A similar description of North Korean-Iranian
cooperation in the Syrian reactor came in two reports from Washington in the Japanese
newspaper, Sankei Shimbun. The newspaper reported in September 2008 information from “a
source familiar with the Syrian nuclear issue” that “a secret Iranian Revolutionary Guards base”
in Iran housed a plutonium reprocessing facility designed to reprocess nuclear fuel rods from the 32
Syrian reactor. Sankei Shimbun reported from Washington in July 2008 several visits of Iranian 33
officials to the Syrian reactor in 2005 and 2006.
Additional information pointing to North Korean-Iranian collaboration in plutonium nuclear
development came from European and Israeli defense officials in early 2007. They stated that
North Korea and Iran had concluded a new agreement for North Korea to share data from its 34
October 2006 nuclear test with Iran.
27 Robin Wright, “N. Koreans taped at Syrian reactor,” Washington Post, April 24, 2008, p. A.1.
28 “U.S. called N. Korea’s bluff over Syria,” Chosun Ilbo (internet), April 1, 2008.
29 “N.Koreans killed in Syria during Israeli raid,” Chosun Ilbo (internet), April 29, 2008. “N. Koreans may have died in
Israel raid in Syria—NHK,” Reuters, April 28, 2008.
30 Nicholas Kralev and Sara A. Carter, “Syria’s nuke facility was nearly finished,” Washington Times, April 24, 2008,
p. A1. Robin Wright, “N. Koreans taped at Syrian reactor,” Washington Post, April 24, 2008, p. A1.
31 “Asad’s risky nuclear game,” Spiegel Online, June 23, 2008.
32 Takashi Arimoto, “Reprocessing facility of bombed nuclear base in Iran; intimate ties between Syria and North
Korea,” Sankei Shimbun (internet), September 12, 2008.
33 Takashi Arimoto, “Iran involved in nuclear program: trilateral cooperation of Syria, Iran, North Korea,” Sankei
Shimbun (internet), July 12, 2008.
34 Jin Dae-woong, “Concerns grow over missile links between N. Korea, Iran,” Korea Herald (internet), January 28,
These reports describe a direct collaborative relationship between North Korea and Iran in
developing nuclear weapons. Additionally, since the early 1990s, a body of reports has
accumulated pointing to a significant collaborative North Korean-Iranian nuclear relationship
inside Iran, with North Korea’s principle interlocutor being the Iranian Revolutionary Guards
(IRGC). Some of these reports cite the Central Intelligence Agency or Western intelligence
sources as sources of information. Other reports seem to be based, at least in part, on Israeli
intelligence sources. Specific events or factors in the alleged North Korean-Iranian nuclear
collaboration are described in multiple reports.
Numerous reports have asserted that the IRGC occupies a leadership role in Iran’s nuclear
program. A State Department’s 2007 Fact Sheet asserted that “the IRGC attempted, as recently as
missile and nuclear program.”
Nuclear collaboration reportedly began at the same time North Korea negotiated with the IRGC
for cooperation in developing and manufacturing Nodong missiles. The first reports, in 1993 and
1994, said that North Korea and Iran had signed an initial agreement for nuclear cooperation. An
Economist Foreign Report cited “CIA sources” that Iran was helping to finance North Korea’s
nuclear program and that North Korea would supply Iran with nuclear technology and 36
equipment. A report of the U.S. House of Representatives Republican Research Committee
claimed that Iran would provide $500 million to North Korea for the joint development of nuclear 37
weapons. The “CIA sources” cited by the Economist Foreign Report mentioned the
development of enriched uranium as a goal of the new North Korean-Iranian agreements.
The next reported stage in nuclear collaboration, in 2003 and afterwards, appears to have been
connected to the reported joint advancement of the program to produce a model of North Korea’s
Nodong intermediate ballistic missile in Iran. Production of the Nodong in Iran was a main
element of the reported North Korean-Iranian agreements of 1993. By 1997, North Korean
missile experts were working in Iran with the IRGC to produce the Shahab 3 and Shahab 4 38
missiles, the Iranian name for the Nodong. Success in developing and testing the Shahab missile
reportedly led to a North Korean-Iranian agreement, probably in 2003, to either initiate or
accelerate work to develop nuclear warheads that could be fitted on the Shahab missile. Iran was
reported to have offered shipments of oil and natural gas to North Korea to secure this joint 39
development of nuclear warheads. North Koreans reportedly were seen at Iranian nuclear
2007. “UK press: North Korea aids Iran in nuclear testing,” Dow Jones International News, January 24, 2007. “Israel
PM to charge NKorea link with Iran, Syria,” Agence France Presse, February 26, 2008.
35 U.S. Department of State, Fact Sheet: Designation of Iranian Entities and Individuals for Proliferation Activities and
Support for Terrorism, October 25, 2007.
36 “An Israeli lesson for North Korea?” Economist Foreign Report, April 22, 1993, p. 2. See also: “DPRK reportedly
aids Iranian nuclear project,” Yonhap News Agency, January 26, 1993. “DPRK military delegation’s Iran visit
reported,” Seoul KBS-1 Radio Network, February 24, 1994.
37 “U.S. report on DPRK-Iran missile deal cited,” Yonhap News Agency, July 16, 1993. The $500 million figure also
was cited in: “Iran funds North Korea’s drive to build nuclear bombs,” U.S. News and World Report, March 29, 1993,
38 Con Coughlin, “China, N. Korea send experts to hone Iran’s long-range missiles,” London Daily Telegraph,
November 23, 1997, p. A5. Bill Gertz, “North Korea send missile parts technology to Iran,” Washington Times, April
18, 2001, p. A3.
39 Douglas Frantz, “Iran closes in on ability to build a nuclear bomb; Tehran’s reactor program masks strides toward a
weapons capability, a Times investigation finds,” Los Angeles Times, August 4, 2003, p. A1. “Military source: DPRK,
facilities in 2003. By this time, a large number of North Korean nuclear and missile specialists 40
reportedly were in Iran. Der Spiegel quoted “western intelligence service circles” as describing
Iran in 2005 as offering North Korea economic aid if Pyongyang “continues to cooperate actively 41
in developing nuclear missiles for Tehran.”
In 2006 and 2008, U.S. intelligence officials, the International Atomic Energy Agency, and other
diplomatic sources disclosed that Iran was trying to modify the Shahab missile, especially the
nose cone, so that it could carry a nuclear warhead. U.S. intelligence officials described this work
as part of an Iranian Project 111—“a nuclear research effort that includes work on missile 42
development.” In March 2006, Reuters reported “an intelligence report given to Reuters by a
non-U.S. diplomat” that described Iran’s plans to develop nuclear warheads for the Shahab 3 43
missile. Two years later, the International Atomic Energy Agency confronted Iran at several
cone of the Shahab-3 missile in order for it to carry a nuclear warhead.
The National Council of Resistance of Iran is an exiled opposition group that in 2002 had
revealed correctly the existence of secret Iranian nuclear facilities at Natanz and Irak. It issued a
report in February 2008 that gave reputed details of North Korean-Iranian collaboration in
nuclear warhead development. It alleged that the Iranian Defense Ministry has a secret facility at
Khojir on the edge of Tehran, code-named B1-Nori-8500, that is engaged in the development of
nuclear warheads for intermediate range ballistic missiles. North Korean specialists are at this 45
facility, according to the National Council.
Another form of North Korean-Iranian nuclear collaboration reportedly involved a huge Iranian
project to develop underground bunkers and tunnels for elements of Iran’s nuclear program. The
project, estimated to have cost hundreds of millions of dollars, included the construction of
10,000 meters of underground halls for nuclear equipment connected by tunnels measuring
hundreds of meters branching off from each hall. Specifications reportedly called for reinforced 46
concrete tunnel ceilings, walls, and doors resistant to explosions and penetrating munitions.
The IRGC implemented the project. North Korea reportedly participated in the design and
construction of the bunkers and tunnels. In early 2005, Myong Lyu-do, a leading North Korean
expert on underground facilities, traveled to Tehran to run the program of North Korean
Iran planning joint development of nuclear warheads,” Sankei Shimbun (internet version), August 6, 2003.
40 “Iranian nuke experts visited N. Korea this year,” Kyodo World Service, June 10, 2003. Douglas Frantz, “Iran closes
in on ability to build a nuclear bomb,” Los Angeles Times, August 4, 2003, p. A1. “Military source: DPRK, Iran
planning joint development of nuclear warheads,” Sankei Shimbun (internet), August 6, 2003.
41 “Mullahs helping Stalinists,” Der Spiegel (internet), November 28, 2005.
42 Dafna Linzer, “Strong leads and dead ends in nuclear case against Iran,” Washington Post, February 8, 2006, p. AO1.
43 Louis Charbonneau, “Iran said to step up plans for Shahab missiles,” Reuters, March 6, 2006.
44 David E. Sanger, “Nuclear agency says Iran has used new technology,” New York Times, February 23, 2008, p. A3.
Mark Heinrich, “IAEA shows photos alleging Iran nuclear missile work,” Reuters, September 16, 2008.
45 “Iran still developing nuclear warheads: exiled opposition group,” Agence France Presse, February 20, 2008. Marc
Champion, “Iran arms claim is lodged—Tehran is developing nuclear warheads, exile group tells U.N.,” Wall Street
Journal Asia, February 21, 2008, p. 9. Koki Mirua, “Anti-Iranian government organ points to ‘DPRK’s cooperation in
Iran’s nuclear development,’” Tokyo Shimbun (internet), September 24, 2008.
46 “Nukes too deep to hit.” Newsweek, November 3, 2008, p. 8, 10.
assistance.47 North Korea is believed to have extensive underground military installations inside
North Korea. Its collaboration with the IRGC reportedly has involved extensive aid to Hezbollah
in constructing underground military installations in Lebanon. (See CRS Report RL30613, North
Korea: Terrorism List Removal?)
The Japanese newspaper, Sankei Shimbun, reported two visits of high level Iranian officials to
North Korea in February and May 2008. The Iranian delegation included officials of Iran’s
Atomic Energy Organization and National Security Council. The apparent purpose of these visits,
according to the reports, was to ensure that North Korea would maintain secrecy about its nuclear
collaboration with Iran in its negotiations with U.S. Assistant Secretary of State Christopher 48
North Korea’s missile launchings of July 4, 2006, re-focused U.S. attention on North Korea’s
missile program and Pyongyang’s apparent attempts to develop long-range missiles that could
strike U.S. territories. North Korea succeeded by 1998 in developing a “Nodong” missile with a
range estimated at up to 900 miles, capable of covering South Korea and most of Japan. North
Korea reportedly deployed nearly 100 Nodong missiles by 2003 and also had jointly developed
with Iran the Shahab version of the Nodong. On August 31, 1998, North Korea test fired a three-
stage rocket, apparently the prototype of the Taepodong I missile; the third stage apparently was
an attempt to launch a satellite. U.S. intelligence estimates reportedly concluded that such a
missile would have the range to reach Alaska, Guam, and the Northern Marianas Commonwealth.
Media reports in early 2000 cited U.S. intelligence findings that without further flight tests, North
Korea could deploy an intercontinental ballistic missile that would be capable of striking Alaska,
Hawaii, and the U.S. west coast. U.S. officials claimed in September 2003 that North Korea had
developed a more accurate, longer-range intermediate ballistic missile that could reach Okinawa
and Guam (site of major U.S. military bases) and that there was evidence that North Korea had
produced the Taepodong II, which could reach Alaska, Hawaii, and the U.S. west coast.
However, the apparent failure of the Taepodong missile launched July 4, 2006, indicated that
North Korea had not succeeded in developing such a long-range missile. However, evaluations of
all seven of the missiles launched on July 4, 2006, by intelligence agencies of the United States
and other governments reportedly have concluded that North Korea has increased the accuracy of
its Scud and Nodong missiles and that the launches displayed the ability of North Korea’s 49
command and control apparatus to coordinate multiple launchings of missiles at diverse targets.
(For additional information, see CRS Report RS21473, North Korean Ballistic Missile Threat to
the United States, by Steven A. Hildreth.)
The Clinton Administration pressed North Korea for new talks over North Korea’s missile
program. In talks held in 1999 and 2000, North Korea demanded $1 billion annually in exchange
for a promise not to export missiles. U.S. negotiators rejected North Korea’s demand for $1
47 Robin Hughes, “Tehran takes steps to protect nuclear facilities,” Jane’s Defence Weekly, January 25, 2006, p. 4-5.
48 Takashi Arimoto, “Iranian delegation makes top secret visit to North Korea in late February; for discussions on
nuclear issue?” Sankei Shimbun (internet), March 20, 2008. “Iran involved in nuclear program: trilateral cooperation of
Syria, Iran, North Korea,” Sankei Shimbun (internet), July 12, 2008.
49 “An expert is amazed by the targeting accuracy: an exclusive report based on complete data on the landing points of
North Korean missiles,” Yomiuri Weekly (Tokyo) in Japanese, August 6, 2006. p. 22-23.
billion but offered a lifting of U.S. economic sanctions. This laid the ground for the Berlin
agreement of September 1999, in which North Korea agreed to defer further missile tests in return
for the lifting of major U.S. economic sanctions. President Clinton formalized the lifting of key
economic sanctions against North Korea in June 2000. North Korea continued the moratorium,
but it appears to have used Pakistan and Iran as surrogates in testing intermediate-range missiles 50
based on North Korean technology.
A CIA statement of August 18, 2003, reportedly estimated that North Korea had produced one or
two simple fission-type nuclear weapons and had validated the designs without conducting yield-51
producing nuclear tests. The initial estimate of one or two nuclear weapons is derived primarily
from North Korea’s approximately 70-day shutdown of the five megawatt reactor in 1989, which
would have given it the opportunity to remove nuclear fuel rods, from which plutonium is
reprocessed. The U.S. Central Intelligence Agency (CIA) and the Defense Intelligence Agency
(DIA) reportedly estimated in late 1993 that North Korea extracted enough fuel rods for about 12
kilograms of plutonium—sufficient for one or two atomic bombs. The CIA and DIA apparently 52
based their estimate on the 1989 shutdown of the five megawatt reactor.
South Korean and Japanese intelligence estimates reportedly were higher: 16-24 kilograms
(Japan) and 7-22 kilograms (South Korea). These estimates reportedly are based on the view that
North Korea could have acquired a higher volume of plutonium from the 1989 reactor shutdown
and the view of a higher possibility that North Korea removed fuel rods during the 1990 and 1991
reactor slowdowns. Russian Defense Ministry analyses of late 1993 reportedly came to a similar
estimate of about 20 kilograms of plutonium, enough for two or three atomic bombs. General
Leon LaPorte, former U.S. Commander in Korea, stated in an interview in April 2006 that North
Korea possessed three to six nuclear weapons before the 1994 U.S.-North Korean Agreed 53
Russian intelligence agencies also reportedly have learned of significant technological advances
by North Korea toward nuclear weapons production. On March 10, 1992, the Russian newspaper
Argumenty I Fakty (Arguments and Facts) published the text of a 1990 Soviet KGB report to the
Soviet Central Committee on North Korea’s nuclear program. It was published again by Izvestiya
on June 24, 1994. The KGB report asserted that “According to available data, development of the
first nuclear device has been completed at the DPRK nuclear research center in Yongbyon.” The
North Korean government, the report stated, had decided not to test the device in order to avoid
50 Gertz, Bill. “Pakistan’s missile program aided by North Korea.” Washington Times, September 14, 1998. p. A1.
Alon, Ben-David. “Iran successfully tests Shahab 3,” Janes Defence Weekly (internet version), July 9, 2003. Coughlin,
Con. “China, N. Korea send experts to hone Iran’s long-range missiles, New York Times, November 23, 1997. p. A5.
51 Sanger, David E. “North Korea’s bomb: untested but ready, C.I.A. concludes,” New York Times, November 9, 2003.
52 Edith M. Lederer, “Fuel for speculation; reactor shutdown seen as N. Korean nuke source,” Washington Times,
January 10, 1994, p. 1. David Albright, “North Korean Plutonium Production.” ISIS Paper, 1994, p. 10-13.
53 Kang Chan-ho. “Former USFK commander: transfer of wartime control should not be carried out overnight,” Joong
Ang Ilbo (Seoul), April 3, 2006. p. 13.
Additionally, a number of reports and evidence point to at least a middle-range likelihood that
North Korea may have smuggled plutonium from Russia. In June 1994, the head of Russia’s
Counterintelligence Service (successor to the KGB) said at a press conference that North Korea’s
attempts to smuggle “components of nuclear arms production” from Russia caused his agency
“special anxiety.” U.S. executive branch officials have expressed concern in background briefings
over the possibility that North Korea has smuggled plutonium from Russia. One U.S. official,
quoted in the Washington Times, July 5, 1994, asserted that “There is the possibility that things
having gotten over the [Russia-North Korea] border without anybody being aware of it.” The
most specific claim came in the German news magazine Stern in March 1993, which cited
Russian Counterintelligence Service reports that North Korea had smuggled 56 kilograms of
plutonium (enough for 7-9 atomic bombs) from Russia.
If, as it claims, North Korea reprocessed the 8,000 nuclear fuel rods in 2003 that it had moved
from storage at the beginning of that year, North Korea gained an additional 25-30 kilograms of
plutonium, according to Dr. Sigfried Hecker in his testimony before the Senate Foreign Relations
Committee on January 21, 2004. Dr. Hecker, former director of the Los Alamos Laboratories, had
visited North Korea’s Yongbyon nuclear complex in January 2004. U.S. officials and nuclear
experts have stated that this amount of plutonium would give North Korea the potential to 54
produce between four to eight atomic bombs. Nuclear expert David Albright estimated in
February 2007 that North Korea had a stockpile of reprocessed plutonium of 28-50 kilograms, 55
enough for between 5 and 12 nuclear weapons. These estimates appear to be based on
projections that a country like North Korea would need 6-8 kilograms of plutonium to produce
one atomic bomb. The IAEA has had a standard that a non-nuclear state would need about eight
kilograms of plutonium to produce an atomic bomb.
The question of whether North Korea produced additional nuclear weapons with the plutonium
that it apparently acquired after 2003 may depend on the degree of success/failure of North
Korea’s nuclear test of October 2006 and whether North Korea is able to develop a nuclear
warhead that could be fitted onto its missiles. Experts believe that any atomic bombs developed
likely are similar to the plutonium bomb dropped by the United States on Nagasaki in August
or Japanese target. Thus, Pyongyang probably would not produce additional Nagasaki-type
bombs but would retain its weapons-grade plutonium until it could use it to produce a nuclear
warhead. Statements by U.S. officials reflect an apparent uncertainty over whether North Korea 56
has achieved a warheading capability, and they have not addressed publicly the reports of North
Korean-Iranian collaboration in nuclear warhead development.
According to press reports in late 2002, the CIA concluded that North Korea accelerated its
uranium enrichment program in the 1999, 2000, and 2001. According to U.S. News and World
Report, September 1, 2003, the CIA estimated that North Korea could produce a uranium-based
atomic weapon by the second half of 2004. Another report, in the Washington Post, April 28,
2004, stated that U.S. intelligence officials had “broadly concluded” that a North Korean uranium
54 Kessler, Glenn. “N. Korea nuclear estimate to rise,” Washington Post, April 28, 2004. p. A1. “U.S. Expert says N.
Korea has plutonium to make 8 bombs,” Yonhap News Agency, January 2, 2006.
55 David Albright and Paul Brannan, “The North Korean Plutonium Stock,” Institute for Science and International
Security, February 20, 2007.
56 Cloud, David S. and Sanger, David E. “U.S. aide sees arms advance by North Korea,” New York Times, April 29,
2005. p. A1. Morgan, David. “U.S. not certain North Korea has nuclear weapons,” Reuters, February 28, 2005.
enrichment program would be operational by 2007, producing enough material for as many as six 57
atomic bombs. However, U.S. officials have stated that they know less about the secret uranium
enrichment program (HEU) than they know about the plutonium program. North Korea received
designs for uranium enrichment centrifuges from Pakistan nuclear “czar,” A.Q. Khan, and has
attempted to purchase overseas key components for uranium enrichment centrifuges; but some of 58
these purchases have been blocked. Assistant Secretary of State Christopher Hill stated on
September 28, 2005, that “where there is not a consensus is how far they [North Korea] have 59
gone with this [the HEU program].”
2/13/07—The six party governments negotiating over North Korea’s nuclear programs announced
an agreement for a freeze and disablement of North Korea’s nuclear facilities accompanied by
energy and diplomatic benefits to North Korea.
6/25/07—A diplomatic deadlock involving $24 million in frozen North Korean funds in a Macau
bank, Banco Delta Asia, was ended when U.S.-initiated measures to unfreeze the money and
transfer it to North Korea.
7/18/07—The International Atomic Energy Agency announced that nuclear facilities at Yongbyon
are shut down in accordance with the freeze provisions of the February 2007 six party nuclear
10/3/07—The six parties issued a statement to implement the second phase of the February 2007
nuclear agreement, focusing on the disablement of Yongbyon, a North Korean declaration of its
nuclear programs, and a U.S. promise to lift economic sanctions on North Korea and remove
North Korea from the U.S. list of state sponsors of terrorism.
4/8/08—Assistant Secretary of State Christopher Hill and North Korea’s Kim Kye-gwan
negotiated an agreement reportedly limiting the information that North Korea would have to
provide in a declaration of nuclear programs.
6/26/08—North Korea transmitted a declaration of nuclear programs to China, the chairman of
the six party talks. President Bush announced a lifting of economic sanctions on North Korea and
an intention to remove North Korea from the U.S. list of state sponsors of terrorism by August 11,
8/11/08—The Bush Administration announced that it would not remove North Korea from the list
of state sponsors of terrorism because Pyongyang rejected U.S. proposals for a verification
system of inspections inside North Korea.
57 Kessler, “N. Korea nuclear estimate to rise,” Washington Post, April 28, 2004. p. A1.
58 Albright and Hinderstein, Dismantling the DPRK’s nuclear weapons program, pp. 35-36.
59 “Parties concur N.K. has HEU material, but disagree on program’s progress: Hill,” Yonhap News Agency,
September 29, 2005.
10/3/08—Assistant Secretary of State Hill and North Korean officials negotiate an agreement in
Pyongyang for a verification system.
CRS Report RL31555, China and Proliferation of Weapons of Mass Destruction and Missiles:
Policy Issues, by Shirley A. Kan.
CRS Report RL31785, Foreign Assistance to North Korea, by Mark E. Manyin.
CRS Report RL33567, Korea-U.S. Relations: Issues for Congress, by Larry A. Niksch.
CRS Report RL31696, North Korea: Economic Sanctions, by Dianne E. Rennack.
CRS Report RS21473, North Korean Ballistic Missile Threat to the United States, by Steven A.
CRS Report RL33324, North Korean Counterfeiting of U.S. Currency, by Dick K. Nanto.
CRS Report RL33709, North Korea’s Nuclear Test: Motivations, Implications, and U.S. Options,
by Emma Chanlett-Avery and Sharon Squassoni.
CRS Report RS21391, North Korea’s Nuclear Weapons: Latest Developments, by Sharon
Larry A. Niksch
Specialist in Asian Affairs