North Korea raises the stakes

Pyongyang’s warning that it may detonate a hydrogen bomb over the Pacific has added a grave new dimension to the Korean crisis. North Korean foreign minister Ri Yong-ho’s warning coincided with a fresh torrent of invective from despot Kim Jong-un, who promised to “tame the mentally deranged US dotard with fire”. He threatened retribution against Donald Trump “beyond his expectation”. Given North Korea’s record, Asia-Pacific nations must take such threats extremely seriously.

International support is vital for sweeping new sanctions, announced by Mr Trump, that will cut off banks and enterprises, regardless of nationality, from doing any business with the US if they deal with Pyongyang. The measures coincide with the highly significant disclosure by Mr Trump that Chinese leader Xi Jinping has finally got tough with North Korea. He has told Beijing’s central bank to bar all financial institutions from doing any business with North Korea. Given 90 per cent of Pyongyang’s trade is through China, that restriction should have a major impact. As Pyongyang’s verbal aggression reaches dangerous new levels, it remains to be seen whether such long overdue sanctions can work in time to forestall a conflict.

A measure of what is at stake in Mr Ri’s dire warning is the massive underground explosion on September 3 that US officials have confirmed was a hydrogen bomb. Japanese Prime Minister Shinzo Abe said it was far “beyond the scale of Hiroshima”. North Korea’s intention is to fit the hydrogen bomb to its new intercontinental ballistic missiles.

The US has a clear responsibility to itself and to its allies across the region to deal decisively with whatever military threat eventuates, be it to Guam, Japan or South Korea. As well, the international community must join in the sweeping new sanctions that have finally brought the US and China together in an effort to bring Kim to his senses. The sanctions must be applied rigorously, without exception. The warning about a hydrogen bomb detonation over the Pacific has raised the stakes immeasurably.