North Korea is widely recognized as being years away from perfecting the technology to back up its bold threats of a pre-emptive strike on the United States. But some nuclear experts say it might have the know-how to fire a nuclear-tipped missile at South Korea and Japan, which host US military bases.
No one can tell with any certainty how much technological progress North Korea has made, aside from perhaps a few people close to its secretive leadership.
The North's third nuclear test on Feb. 12, which prompted the toughest UN Security Council sanctions yet against Pyongyang, is presumed to have advanced its ability to miniaturize a nuclear device. And experts say it's easier to design a nuclear warhead that works on a shorter-range missile than one for an intercontinental missile that could target the US.
The assessment of David Albright at the Institute for Science and International Security think tank is that North Korea has the capability to mount a warhead on its Rodong missile, which has a range of 800 miles (1,280 kilometers) and could hit South Korea and most of Japan. But he cautioned in his analysis, published after the latest nuclear test, that it is an uncertain estimate, and the warhead's reliability remains unclear.