N. Korea’s H-bomb threat raises questions about risks

Robert Burns and Matthew Pennington
Associated Press

Washington — Would exploding a hydrogen bomb over the Pacific, as North Korea has threatened, push the current war of words between the U.S. and North Korea closer to actual war?

People walk past images showing North Korean missile test launches on display outside the central railway station in Pyongyang on September 22, 2017.

As with much that has transpired lately in the U.S.-North Korea nuclear crisis, no one can be sure where this would lead or whether the North will even carry out its threat. It does, however, raise many questions, including: How would the North undertake such a nuclear test, what risks might it pose to Japan and how would the U.S. respond?

After the North Korean leader, Kim Jong Un, said President Donald Trump would “pay dearly” for threatening to “totally destroy” North Korea if the U.S. were forced to defend itself or its allies against a North Korean attack, Kim’s foreign minister told reporters his country’s response to Trump “could be the most powerful detonation of an H-bomb in the Pacific.”

All six of North Korea’s nuclear tests thus far, dating to 2006, have been conducted in underground tunnels.

Experts say the most likely way the North would conduct an atmospheric test over the Pacific is to launch a long-range missile — probably overflying Japan — and have its nuclear warhead detonate in the skies over a remote part of the Pacific.

“I strongly suspect they have the capability to do this,” said James Acton, a nuclear expert at the Carnegie Endowment for International Peace. He said in a telephone interview that the North likely would do a couple of trial runs with unarmed missiles in coming months before performing the test with an actual H-bomb aboard.

Such a test with a live warhead would tell North Korea’s engineers whether their bomb design can survive the rigors of flight and re-entry into the Earth’s atmosphere, says Michael Elleman, a missile defense expert at the International Institute for Strategic Studies.

North Korea has said it intends to build a missile capable of striking all parts of the United States with a nuclear bomb. Trump has said he won’t allow it.

Susan Thornton, the acting secretary of state for East Asia and the Pacific, said Friday a North Korean H-bomb test in the Pacific would be “outrageous.”

North Korea says it needs nuclear weapons to deter a U.S. invasion, but Thornton contended that the North ultimately seeks to take over U.S.-allied South Korea.

She said Kim’s aim in developing nuclear weapons is “to fulfill a long-term desire on the part of the North Korean regime to reunify the Korean Peninsula under the Kim family regime and proliferate these weapons and blackmail other countries. This is an intolerable prospect that no other country in the international community can abide.”