North Korea’s capacity unclear

WASHINGTON – North Korea announced Monday that it had tested a nuclear weapon underground. Here are some questions and answers about the significance of that announcement.

Q.How do we know that North Korea actually detonated a nuclear device?

A.We don’t. We know only that the North Korean government said it did and that a seismic event was detected in northeastern North Korea. The U.S. Geological Service measured the event at magnitude 4.2; the South Koreans said the magnitude was 3.6.

Q.Does North Korea have the nuclear fuel to make actual bombs?

A.It does. The Institute for Science and International Security in Washington, D.C., says it has enough plutonium for between four and 13 weapons, depending on size.

Q. Does the test mean that North Korea can deliver nuclear bombs to targets in the United States?

A. Probably not. North Korea is generally thought to lack the missiles it would need.

Q.Then why so much concern?

A.The North Koreans could do a lot of mischief short of attacking the United States. For one thing, they could use the bomb as a deterrent to U.S. military action against them. They could threaten to respond to an American attack by striking Japan, South Korea or another nearby U.S. ally. That prospect could lead to an arms race between North Korea and U.S. allies in Asia.

Q.What about the possibility North Korea would give or sell its nuclear technology and materials to some of the world’s other bad guys?

A.That’s another problem. The North Koreans dropped out of the Nuclear Nonproliferation Treaty nearly four years ago.

Q.How many countries now have nuclear weapons?

A.Besides the United States and – presumably – North Korea, the nations known to possess nuclear weapons are Britain, France, Russia, China, India and Pakistan. Israel is widely thought to have them.