Leading article: Brown's duty to the forces

We are in a twilight period of politics, where Tony Blair makes the arguments but Gordon Brown makes the decisions. This curious arrangement is most evident in defence and security policy. Recently, the Prime Minister made the argument for keeping open the option of renewing the Trident nuclear weapons programme, while the Chancellor nodded and agreed to honour the cheques, which will start to be presented after he moves next door.

Last week, the pattern was repeated. On Friday, the Prime Minister made an eloquent case on behalf of the armed forces for a higher share of public spending. He asked the nation to endorse a foreign policy that would require the use of military force in order to defend global and, therefore British, security. Put like that, The Independent on Sunday supports him. We have always drawn a rigorous distinction between Afghanistan, where the use of force was and remains justified and necessary, and Iraq, where it was not. We do not advocate a neutralist foreign policy, and want our armed forces to be capable in principle of deployments on the current scale.

This newspaper has been as forthright in its praise for the bravery of our service personnel, in every theatre, as it has been in its condemnation of Mr Blair's decision to join the US invasion of Iraq. If we want a stronger role for the United Nations in enforcing international law - and we do - then countries such as Britain have to be prepared to deploy soldiers to make it happen. Nor should we forget that British forces still have an enviable reputation for peace-keeping, as well as for war-fighting.

We agree with the Prime Minister that the British people should decide what they want their armed forces to do, and then give them the equipment needed to do it. We have argued strenuously that our soldiers should be given the tools to finish the job - even if, in Iraq, it is not a job that should have been started. However, it is the Chancellor who will decide, not just as Chancellor but as a prime minister whose elevation will coincide, more or less, with the Comprehensive Spending Review in July.

It is Mr Brown, then, who will have to take the hard decisions about what precisely Mr Blair's plausible rhetoric means in numbers with pound signs in front of them. And there are at least two subjects over which Mr Blair glossed unconvincingly. One is the Royal Navy and the other is the Eurofighter project. Although he tried to coddle his audience on a new ship with amphibious capabilities in Plymouth, he did not begin to make the case for why the navy needs so many expensive vessels. How are new aircraft carriers, destroyers and attack submarines going to help in the fight against al-Qa'ida? We do not say that they are not needed, only that the case was not made last week by the outgoing Prime Minister. The same question could be asked of new fighters for the Royal Air Force, which Mr Blair did not even mention, perhaps because he was not speaking to an RAF audience.

In the long term, therefore, it is possible to imagine savings that could be made on some of the hardware of traditional inter-state conflict - which is, incidentally, where costs are rising fastest and where the Ministry of Defence has the worst procurement record. But in the short term, the pressing need for better pay, housing and equipment for troops on longer tours of active service is bound to require higher defence spending for the foreseeable future.

Mr Blair has asked the right questions, and has started to provide some of the right answers. He has, however, still left some of the trickier nettles for his successor to grasp. It will be a test of Mr Brown's leadership that he asks searching questions about the value for money obtained on large, over-specified, hi-tech defence projects. But for now everyone should be agreed that, in contrast, spending on pay and living conditions for squaddies can never be money misspent.