Leading article: A failure of politics, not personnel

Defence procurement by the British Government is widely accepted to be an expensive mess. In recent years it has been a tale of massive over-expenditure, apparently non-existent cost control, and lamentable judgement on military priorities. Billions of pounds have been spent on the Eurofighter, a plane designed to fight Russian jets in a hypothetical future war, while troops in an all too real conflict in Afghanistan today go under-resourced, lacking body armour, helicopters and other vehicles. An internal report by Bernard Gray, a former Ministry of Defence (MoD) special adviser, is believed to have identified £2.5bn in waste a year.

So who has been held accountable for this fiasco? Which heads have rolled for this incompetence? Well, it turns out that one senior military head will indeed roll this year, the Chief of the Defence Staff, Sir Jock Stirrup. Sir Jock was asked to extend his term by the previous government to April 2011. Now he will go this autumn after the long-awaited Strategic Defence Review has been completed. The MoD's top civil servant, Sir Bill Jeffrey, will also leave at the same time.

Whether these are the right officials to carry the can for the shambles at the MoD or not is open to debate. But Sir Jock's early departure is not to be lamented. Even if blame for the procurement scandal cannot reasonably be laid at his door, he is hardly the individual to usher in a new, more fiscally disciplined era at the MoD. The next Chief of the Defence Staff must not be compromised by the old regime.

Yet we need to be clear that the key to restoring financial discipline in defence expenditure is not top personnel, but political direction. Cost control obviously matters, but not as much as decisions on which projects to invest in. And those judgements are, at heart, political, because they are inextricably linked to the question of what our armed forces should be doing in the world. Officials cannot make those decisions, only governments can.

There is a tension within the Conservative side of the coalition on defence. There are those who want Britain to have a Tony Blair-style interventionist foreign policy and an expensive nuclear deterrent, and there are those who are fixated on reducing public expenditure as a national priority. They cannot both prevail. There must be a choice. And no unfortunate general, admiral or air chief marshal can be asked to carry the can if they get it wrong.