Did Pyongyang Drop the H-Bomb?

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Five questions about today’s nuclear news from North Korea

Did Pyongyang Drop the H-Bomb?

1Did they really do what they said they did?

Today North Korea announced that it had conducted a successful test of a hydrogen bomb. Government officials and independent analysts question this claim as the explosion resembled a one-stage atomic weapon —the same sort the North detonated in three previous tests (2006, 2009, and 2013). Since the North made inflated statements about these earlier tests, it would be no surprise if its H-bomb claim were an exaggeration. As of now, it seems likely that North Korea detonated a “boosted-fission bomb,” which involves using a small amount of tritium to increase the yield of a standard fission (or atomic) bomb. This would be a technical advance, but nothing like what Pyongyang claimed. In the next day or two, seismologists should know depth of the quake caused by the test and be able to work out the precise yield of the blast. Meanwhile the Comprehensive Test Ban Treaty Organization and various countries are trying to detect the signature radionuclides that will help them decode the bomb.

2What is a hydrogen bomb and why does it matter whether Korea has tested one?

A hydrogen bomb is far more powerful than a fission bomb. It's a thermonuclear weapon that uses an atomic reaction as a trigger to create a massive secondary explosion from the nuclear fusion of hydrogen isotopes. This type of bomb can generate explosions ten to a thousand times more powerful than the fission weapon dropped on Hiroshima.

3 Does this change the status quo?

Not much, if the early hypotheses are confirmed. However continued progress by North Korea in boosting would advance its efforts to miniaturize its warheads and make them easier to deliver and deploy. That would have significant implications for the U.S and Korea’s neighbors.

4Why did North Korea conduct this test now?

Many North Korea watchers have been expecting this sort of test. In fact, commercial satellites detected activity at the Punggye-ri test site in December. North Korea typically uses its nuclear tests to send a message or commemorate an anniversary. Kim Jong Un's birthday is on Friday, which might explain the timing. A successful test could strengthen Un’s standing in advance of the highly anticipated Congress of the Korean Workers' Party, which will meet in May for the first since 1980.

5How will China likely respond?

On Wednesday, a spokeswoman for the Chinese Ministry of Foreign Affairs offered what the New York Times termed “unusually harsh remarks,” declaring that “China strongly opposes this act” and “will firmly push for denuclearization of the Korean Peninsula.” This response matters, since North Korea depends on China for its political and economic survival. North Korea’s past tests have been a headache for Beijing and a rebuke to Chinese efforts to minimize risks and encourage economic reforms in the hermit kingdom. While Beijing will voice criticism, its primary worry is a North Korean collapse and it has been reluctant to push Pyongyang too hard.

Whether Pyongyang’s most recent provocative actions will lead Beijing to respond more forcefully than in the past, remains uncertain. Despite the risks involved, some analysts believe that China has not opposed North Korea’s nuclear activities because of the distraction it poses for U.S. geostrategic plans in the region. Others contend that China’s increased involvement with South Korea and Japan has begun to temper their continued support for North Korea and that China understands that North Korea’s involvement with nuclear weapons remains the most destabilizing threat to the regime because of the possibility of international intervention.