By Dr Robert Crowcroft

The leak of a confidential letter written from Liam Fox to David Cameron has now been widely picked up in the press. The upshot is Fox's complaint that the Strategic Defence Review process is fast losing credibility and coherence – because of the Treasury's willingness to subordinate national security to a timetable chosen by Cameron and George Osborne for very political reasons – to try get the bad news out of the way, in one go, in the Comprehensive Spending Review. While one has to admire the political gusto of Cameron – and in the unlikely event he pulls it off, it would constitute a masterstroke – nonetheless Fox is right: that these kind of grave decisions cannot be taken in such a short space of time (while Guardianistas will vomit righteous indignation, the fact is that Defence is different from other departments, i.e. more important), and that there has been an inadequate scope for debating the future of Britain's role in international politics.

The basic problem is this: the UK is currently engaged in a war in Afghanistan, and will be there for about five more years. This requires proper funding of the ground forces which wage counterinsurgency conflicts. However, to fund the Afghanistan commitment, the Army will need to be shielded while the other services are squeezed – the aircraft carriers potentially face the axe, as do other classes of surface vessel, several kinds of aircraft, and even the Trident submarines. The strategic dilemma facing the country is whether future security crises requires long-term occupation and nation-building on the Afghanistan model, or whether the threat, and demands on the UK, will look quite different. If the future is not more Afghanistans, then favouring the ground forces now by badly weakening the naval and air power available to the country risks calamitous damage.