"North Korea's decisions to restart nuclear installations at Yongbyon that were shut down under the U.S.-North Korean Agreed Framework of 1994 and to withdraw from the Nuclear Non-Proliferation Treaty create an acute foreign policy problem for the United States. Restarting the Yongbyon facilities opens up a possible North Korean intent to stage a 'nuclear breakout' of its nuclear program and openly produce nuclear weapons. North Korea's actions follow the reported disclosure in October 2002 that North Korea is operating a secret nuclear program based on uranium enrichment and the decision by the Korean Peninsula Energy Development Organization (KEDO) in November 2002 to suspend shipments of heavy oil to North Korea. North Korea claims that it has nuclear weapons and that it has completed reprocessing of 8,000 nuclear fuel rods. U.S. officials in 2004 stated that North Korea probably had reprocessed most or all of the fuel rods and may have produced 4-6 atomic bombs from them. […] The crisis is the culmination of eight years of implementation of the 1994 Agreed Framework, which provides for the shutdown of North Korea's nuclear facilities in return for the annual delivery to North Korea of 500,000 tons of heavy oil and the construction in North Korea of two light water nuclear reactors."
CRS Issue Brief for Congress, IB91141