TOKYO — North Korea's underground nuclear test shows it is making big strides toward becoming a true nuclear power. But it also may reveal key clues the secretive nation might have hoped to hide about how close, or how far away, it is from fielding a nuclear weapon capable of striking the United States or its allies.
Hoping to capitalize on a rare opportunity to gauge North Korea's nuclear capabilities, intelligence and military officials around the region are scrambling to glean data to answer three big questions: how powerful was the device Pyongyang tested, what sort of device was it, and what progress does the test indicate the nation has made.
North Korea has hailed Tuesday's test as a perfect success, saying it used a device that was stronger and more advanced than those its past two attempts. Add that to its successful rocket launch in December and the threat of a North Korea ready to strike at the United States, which it sees as its arch-enemy, would appear to be more real than ever.
But just how close is it?
The main thing intelligence officials want to figure out is what kind of device was used. Was it a plutonium bomb, such as the ones it tested in 2006 and 2009, or one that used highly enriched uranium?
James Acton, an analyst with the Carnegie Endowment for International Peace, said North Korea's plutonium stockpile is small and it would be difficult and expensive for the North to produce more. But a test using highly enriched uranium, which is cheaper and easier to produce, would raise the threat that North Korea can expand its nuclear arsenal quickly.