Editorial: Trident and North Korea - Mr Cameron is jumping the gun

A report on the Government's nuclear options is not due until June

If the timing of an escalating nuclear threat can ever be said to be fortuitous, then the latest belligerence from North Korea is – from David Cameron's perspective, at least – just that.

Even without Kim Jong-un's approval of atomic strikes on the US, the return of Britain's 100th nuclear submarine mission presented the Prime Minister with opportunities. Sure enough, Mr Cameron used the occasion as the pretext for a newspaper column making the case for a complete renewal of Trident – at a single stroke both buffing up his core Tory values and emphasising the distance between him and his less gung-ho coalition partners.

Nor do the politics of the nuclear deterrent begin and end with the 2015 general election. The Prime Minister used yesterday's visit to Scotland – where Trident is based – to argue that the country's 12,000-plus defence jobs rely on its remaining a member of the UK. Given that Alex Salmond has salted his noisy campaign for Scottish independence with the promise to close the Westminster Government's submarine base on the Clyde, Mr Cameron's talk of jobs and GDP is far from academic.

With such domestic battles to fight, the pugnacious Mr Kim provides useful ballast, giving real-world oomph to the Prime Minister's claims that "it would be foolish to leave Britain defenceless against a growing nuclear threat". Stripped of its emotional appeal, however, the assertion that North Korea would be more of a risk if we had no atomic weapons is a questionable one. Indeed, even if you accept the claim, Mr Cameron is getting ahead of himself.

The Trident question has no easy answer, pitting a nigh-unaffordable £100bn price tag against a loss of political, military and industrial might, with any number of possible compromises. With the report on the Government's nuclear options not due until June, Mr Cameron not only appears to have pre-empted his own review; his precipitousness also suggests that he has made up his mind before he has the full facts. Neither inspires confidence.