Only China can stop North Korea from Becoming a Full Nuclear Power

IT IS hard to see what might deflect North Korea from becoming a fully-fledged nuclear power. On February 7th it fired an Unha-3 satellite launch rocket into space, just one month after the test of a nuclear device that the North claimed, somewhat unconvincingly, was a hydrogen bomb. The expressions of outrage from the international community and regional neighbours, particularly Japan and South Korea, were the same then as now. The UN Security Council duly held an emergency meeting. America’s secretary of state, John Kerry, repeated his calls for additional international sanctions against North Korea, which were rejected by the rogue state’s only supposed ally, China.

The launch of the three-stage rocket, the second since December 2012, is widely seen as part of a programme to develop an inter-continental ballistic missile (ICBM). Experts believe that if modified to carry a 2,200-pound (1,000-kg) warhead instead of a satellite, the Unha-3 could reach Alaska and possibly Hawaii. However, to get a usable ICBM, North Korea’s scientists will have to master additional technologies. First, they must make a nuclear warhead small enough to be accommodated on the missile. Second, they will have to design and build a re-entry vehicle to carry the warhead to its target. Neither will be easy, but the assumption must be that they will get there in the end—perhaps sooner rather than later—if nothing happens to change the strategic calculus of the regime of Kim Jong Un that nuclear weapons are the ultimate guarantee of its survival.

The only thing that might do that is for China to threaten to pull the plug on the fragile economy of the hermit kingdom by ordering its banks and companies to stop doing business there. Despite Mr Kerry’s pleas, there is not the slightest sign of that happening. Beijing expressed “regret” over the launch, but argued that “dialogue” was the way to ensure a lasting peace on the Korean peninsula. China fears that were the regime to collapse it would be faced with both a flood of refugees over the border into its north-east and the removal of a useful buffer between it and America’s ally in the south.

The current situation is not without cost for China. It is embarrassing for it to have so little influence over the actions of its smaller neighbour. It will also regard with alarm America’s willingness to improve South Korea’s anti-missile defences. A consequence of Sunday’s launch is that South Korea is now almost certain to acquire the Terminal High-Altitude Air Defence (THAAD) system to add to the Aegis system it already deploys on naval destroyers. America says that THAAD will only be focused on the threat from North Korea, but the Chinese fear that, if integrated with systems operated by Japan and America, it would undercut the effectiveness of its own missile forces.

China is not ready to call Mr Kim to heel, however. Perhaps another reason it may be reluctant to try is that it is not sure that he would comply.