The crisis surrounding North Korea's nuclear programme has been further deepened by the test of what it says is a hydrogen bomb on Sunday, followed by international condemnations and arguments about how to respond. Choices between tougher sanctions, more diplomacy or military deterrence and action are posed amid mounting concern that impulsive moves by Donald Trump or Kim Jong-un could make the escalation of tension even more serious.
None of these means have stopped the North Korean rush towards an advanced nuclear capability. Deciding whether this push is motivated by genuine fear of attack, real willingness to bargain or an irrational craving for power by its young leader is difficult even for specialists. These events underline yet again how complex is the regional setting in which it occurs and how fraught and unpredictable it would be to take decisive action against North Korea's leadership. The pressure to take such action is becoming more intense. The United Nations Security Council is considering adding textiles, air travel bans and more extensive blacklisting to its repertoire of sanctions. President Trump would like to add a ban on crude oil exports, but China fears that could push the regime towards collapse. President Xi Jinping must be further worried by Trump's threats to stop trading with those who support North Korea, just as his South Korean counterpart president Moon Jae-in has to assess Trump's call to abrogate the US trade agreement with his country.
The latest North Korean escalations have forced Moon to cooperate with the US anti-ballistic missile system despite his earlier reservations. But his long-term commitment to a peaceful denuclearisation on the Korean peninsula remains a policy worth pursuing. Diplomatic and political efforts to bring about multilateral talks on how this might be achieved should continue to drive international involvement in this crisis. China, South Korea and Japan have huge responsibilities to make that happen in their own self-interest and to protect their region from an ill-considered or impulsive war.