Analysts Say Blast Was Small for a Nuclear Weapon

Even as North Korea came under international condemnation today after boasting that it had tested a nuclear device, there were serious doubts about the strength of the weapon.

“We have assessed that the explosion in North Korea was a sub-kiloton explosion,” said the intelligence official, speaking on condition of anonymity because of the sensitivity of the issue. He added, “We don’t know, in fact, whether it was a nuclear explosion.” He spoke as intelligence analysts in Washington were in the early stages of assessing the explosion.

A one-kiloton blast would be extremely small for a nuclear weapon. But regardless of the size of the blast, the North Korean announcement reverberated throughout the world of diplomacy, and seemed likely to be felt in American domestic politics as well. There were suggestions, moreover, that the Communist state might be preparing a second test.