This article from the New Scientist explains the difficulties in evaluating an underground nuclear test like North Korea’s. So far, it seems as if the test was less than completely successful, but if there was any nuclear component to the explosion, it is confirmation that the North Koreans have achieved one of the most difficult elements of the process of building an atomic bomb, separating out the plutonium.
A bomb made of enriched plutonium is easier to build and explode, but the uranium is harder to produce. Plutonium is not easy, because it is made from the highly radioactive waste products of a nuclear reactor. But the reactor and the separation facilities are easier to build than the temperamental centrifuges or very energy intensive processes needed to produce highly enriched uranium.
So, if the North Koreans have produced enough plutonium to use some to test a nuclear explosive device, then they are well along in the process, even if they don’t have a deliverable bomb. It is possible that some of the Pakistani nuclear tests were also less than 100% successful.
The fact that North Korea has reached this level, whatever it turns out to be exactly, is a grave indictment of Bush’s nuclear non-proliferation policy. The Clinton administration had an agreement in place the capped North Korea’s plutonium production capability. When some evidence turned up that North Korea was working on uranium enrichment, we (the US) threw as hissy fit, and abandoned the cap on plutonium. So, now North Korea is close to having a plutonium bomb, although there is no indication that they are making much, if any, progress on a uranium bomb. We threw out the baby with the bathwater, and now we will reap the whirlwind, to mix some metaphors. The incompetent architect of this policy is UN Amb. John Bolton, who was Under Secretary of State for non-proliferation for years before he went to the UN.
This is a failure for which the administration should be pilloried. It was unnecessary and shows gross incompetence. It was brought to you by the same incompetents who brought you the Iraq war. We are less safe, but we didn’t need to be. Abandoning the Clinton initiatives has brought us closer to nuclear war in Asia, which could spread to the US. Or, North Korea, which tends to sell anything it has on the black market, may sell nuclear weapons, or perhaps just components to terrorists or to other rogue regimes.