N.Korea's Nuclear Missile Threat Under the Spotlight

Assessing the threat North Korea's ballistic missiles pose to the U.S depends on whether they are capable of reaching the U.S. mainland and whether it is able to install nuclear warheads on them.

To make an intercontinental ballistic missile that can reach the U.S. mainland, the North needs to be able to launch a smaller warhead payload. But the smaller, the weaker the payload will be. That is why the North continues to develop nuclear warheads rather than conventional ones.

The official position of the South Korean and U.S. governments and militaries is that the North has not yet reached a stage when it can install such warheads on missiles.

It was confirmed through two underground tests that the North has nuclear bombs. But only an IL-28 bomber could carry such bulky nuclear weapons for now. If nuclear warheads are to be installed on ballistic missiles, they need a diameter of 88 cm to 1 m and a weight of 700-1,000 kg. This would require a massive technological leap forward.

However, some South Korean and foreign experts disagree. Abdul Qadeer Khan, the "father" of Pakistan's nuclear bomb, has testified that during his visit to the North in 1999 he saw three small nuclear bombs and detonators kept in a cave in a mountain and that these small weapons were capable of being installed on missiles.

At a seminar hosted by the Institute for Corean-American Studies last October, David Albright, the president of the Institute for Science and International Security, said he believes that although it has not actually made small nuclear weapons yet, the North must have made progress in developing nuclear warheads that can be installed on ballistic missiles.

And nuclear expert Kim Tae-woo of the Korea Institute for Defense Analyses said, "The North must have significantly developed its technology to make smaller nuclear warheads by now considering that it has conducted research on the technology for decades."