Several months ago, the International Atomic Energy Agency Director General Mohamed ElBaradei raised eyebrows during an interview on CNN regarding the situation in North Korea:
AMANPOUR: Could they be making bombs right now?
ELBARADEI: It is not at all excluded because they have that plutonium they can readily use into nuclear weapon, they have the industrial infrastructure, but more importantly they said they are doing it. So based on our technical assessment we see no technical barrier that they could be able or already have nuclear weapon.
AMANPOUR: In terms of a nuclear weapons menace, which is more threatening now, Iran or North Korea?
ELBARADEI: We know North Korea has the plutonium that can go already into a bomb. We have not seen any such material in Iran. That is why I am saying unless you have the nuclear material you can not have the weapon, you might have the intention, you might have the ambition but unless you have the nuclear material for the bomb, you cannot have the bomb in short span of time. In North Korea they have the material, in Iran we have not seen such material. So, there is a vast difference. When we talk about North Korea, we talk about an imminent threat or an imminent danger; when we talk about Iran we talk about suspicion of a nuclear program ambition. There is a big difference there.
(Emphasis mine. Punctuation added for clarity.)
He elaborated upon his points in another CNN interview on Sunday, which was reported by the UK Guardian. In the IAEA's estimate, North Korea has enough plutonium for five or six nuclear bombs.
It's anyone's guess why the Bush administration is paying more attention to Iran than to North Korea. They sure as hell are ignoring most of the nuclear experts.
Some of their analysis is presented below the fold.
The May/June 2005 edition of the Bulletin has a fantastic article on North Korea's nuclear program. It reinforces ElBaradei's convictions, with plenty of detail. It's a very long article, so I'll just touch on the basics. Definitely read the whole thing, though, as well as the references to which the numbers in brackets refer.
On February 10, North Korea announced for the first time that it possesses nuclear weapons.  The claim grabbed headlines, but it is difficult to substantiate. In the early 1990s, the CIA concluded that North Korea had effectively joined the nuclear club by building one or possibly two weapons from plutonium it produced before 1992.  Yet North Korea has never conducted a nuclear test, and although it has extracted weapon-grade plutonium, it has never conclusively demonstrated that it possesses operational nuclear warheads. (Nor has the United States been able to verify it.) It is known, however, that Pyongyang has a nuclear program. By cataloging the program's capabilities and quantity of separated plutonium, it is possible to estimate how many nuclear weapons Kim Jong Il's country might have.
North Korea's probable possession of nuclear weapons presents a serious and extremely complicated problem, with implications that could drastically affect Asian security and, by extension, U.S. interests as well. By violating the Nuclear Non-Proliferation Treaty (NPT), North Korea has weakened the treaty and sent signals that obtaining nuclear weapons has geopolitical benefits, at least when confronting the United States.
Both ElBaradei and any nuclear arms specialist worth his or her salt always emphasize repeatedly that the U.S. hasn't been able to conclusively prove that North Korea has a nuclear program. However, if you look at a timeline of events in North Korea you'll see that many events, from December 2002, when they shut down their reactors, to January 2003, when North Korea withdrew from the nuclear nonproliferation treaty and wouldn't let UN inspectors back into the country, are more than reason enough for alarm.
The the Bulletin article talks about North Korea's potential fissile capabilities:
Intelligence analysts and nuclear experts widely believe that North Korea has produced and separated enough plutonium for a small number of nuclear warheads. Most or all of the plutonium came from reprocessed spent fuel from the 20 MWt reactor at Yongbyon, which went critical on August 14, 1985, and became operational the following January.  The U.S. intelligence community believes that during a 70-day shutdown period in 1989, North Korea secretly removed fuel from the reactor and separated the plutonium. Estimates vary as to how much plutonium was obtained. The State Department believes about 6-8 kilograms; the CIA and Defense Intelligence Agency say 8-9 kilograms; the Institute for Science and International Security estimates as much as 14 kilograms. South Korean, Japanese, and Russian analysts estimate a much larger quantity, ranging up to 24 kilograms.
The article includes a table that outlines how much weapon-grade plutonium can be used for various bomb yields; for example, 6 kg of weapon-grade plutonium can be used to make a 20 kiloton nuclear weapon (for perspective, the plutonium bomb dropped on Nagasaki had a 21 kiloton yield). All of this depends on the technical capability of the North Korean weapons scientists:
No one knows the skill level of North Korean bomb designers. In the 60 years since the Manhattan Project, a large amount of information on nuclear weapons design has become available, and a medium capability certainly seems possible. This would mean that building a bomb with a 1-5 kiloton yield would require about 2 kilograms of plutonium. Weapons with a 10-20 kiloton yield would require approximately 3 kilograms. For several weapons, 8-9 kilograms of plutonium could be enough. During the 1994 North Korean crisis, then-Defense Secretary William Perry said, "If they had a very advanced technology, they could make five bombs out of the amount of plutonium we estimate they have." With 25-30 kilograms of additional plutonium from the 8,000 fuel rods, North Korea could build approximately 6-8 more warheads. A reasonable estimate of the number of assembled North Korean nuclear weapons is up to 10.
What must be emphasized (yet again) is that much of our recent intelligence on North Korea comes from high resolution satellite imagery.
Here's another table from the article. Regarding their ballistic missile program:
The North is working to build a missile with an intercontinental range. The two-stage Taepodong-1 is intended to carry a 1,000-1,500 kilogram warhead up to 2,300 kilometers. Pyongyang launched a three-stage space-launch version of the missile, intended to place a North Korean satellite in orbit, on August 31, 1998, from the facility at Musudan-ri. The missile flew over Japan, causing much consternation. Its first and second stages separated and landed in the water, but the third stage broke up after traveling more than 5,500 kilometers, and the satellite did not reach orbit. Depending on the payload, the as-yet-untested Taepodong-2 may have a range greater than 6,200 kilometers, sufficient to strike parts of Hawaii and Alaska in its two-stage variant, and all of North America in a three-stage variant. It is reasonable to assume that North Korea wants to put nuclear warheads on its ballistic missiles, but whether it has achieved this capability is unknown. Most other countries that have developed nuclear weapons chose airplanes as their initial delivery method, followed in most instances by the development of ballistic missiles of various ranges.
The article ends with some comments on U.S. policies (are you listening, George?):
The current administration's hope that North Korea will give up its nuclear weapons seems fanciful at this point.  What incentives could possibly persuade it to give up its weapons program, dismantle its nuclear complex, and agree to an intrusive verification regime? It seems highly unlikely that North Korea would agree to abandon the very thing that gives it leverage with its neighbors and the United States.
President George W. Bush's first-term policies failed to move North Korea toward the goal of disarmament and instead proved to be counterproductive. Admonitions that North Korea is an "outpost of tyranny" and part of the "axis of evil" have tended to increase the North's already substantial fear and paranoia of the United States. The hardliners around Bush believe that isolation, pressure, and sanctions will cause North Korea to collapse and that it should not be rewarded for any positive steps it might take. The six-party talks, held in August 2003, February 2004, and June 2004, have yielded little. The United States proposed a step-by-step process for further talks, but North Korea recently rejected further negotiations.
Reference  is this:
Senate Select Committee on Intelligence, Current and Projected National Security Threats to the United States, 109th Cong., 1st sess., February 16, 2005. On p. 10, Vice Adm. Lowell E. Jacoby, director of the Defense Intelligence Agency, says that, "Kim Chong-Il may eventually agree to negotiate parts of his nuclear weapon stockpile and program and agree to some type of inspection regime, but we judge Kim is not likely to surrender all of his nuclear weapon capabilities."(click here for the document, PDF).
Nuclear weapons are bargaining power. So is plutonium - it would be worth quite a lot to terrorists with the financial means, not to mention other countries.
Given that North Korea has just shut down another reactor (a prelude to processing more fuel for plutonium), it's time to worry, George. Are you listening?