Leading article: Afghanistan must be debated

The war in Afghanistan has hardly featured in the election campaign so far. One of the merits of the leaders' televised debate on Thursday was that a member of the public asked what they would do about British troops being under-equipped and underpaid. To his credit, Gordon Brown said that, in dealing with that issue, he had another big question that "I've got to answer to the British people for" which was: "Why are we in Afghanistan?" His answer was short and unsatisfactory, but at least he gave it: "We're in Afghanistan because there is a terror threat and a chain of terror that comes from the Afghan-Pakistan border to our country; and three-quarters of the terrorist plots that we identify start not in Britain, start not in Europe, but start in that border area."

But the exchanges between the party leaders focused on helicopters – or, in Nick Clegg's case, "proper helicopters" – and on Mr Brown's semantic argument that he had never refused a request for an "urgent operational requirement" from the Army. Mr Brown was not challenged on his rationale for the British military mission in Afghanistan, because the other two parties agree with it. Voters have to turn to the Green Party, the Scottish National Party and Plaid Cymru to find principled opposition. That means that one of the central questions of foreign policy is in danger of passing through an election campaign by default.

Last week, The Independent on Sunday raised the deficit as a big issue that none of the parties was addressing honestly; this week, we turn our attention to Afghanistan. We became the first national newspaper last November to call for a phased withdrawal of our troops. At the time of Barack Obama's decision to deploy more American forces, we held out against the consensus and argued that the ambition of the international community should be scaled back. Since then, the death toll of British soldiers has continued to rise, reaching 281 last week. British soldiers are doing good and brave work. But they are fighting in a wider battle in which the balance of advantage has shifted.

Getting rid of the Taliban regime nine years ago was justified. Supporting the Afghan people in trying to establish order, security and stability was justified. But propping up Hamid Karzai's corrupt government is harder to justify. And trying to police the entire country indefinitely is harder still. It increasingly provides Islamist nationalists with targets to shoot at and blow up. When Mr Brown, trying to defend the delay in getting helicopters, said that the Taliban had changed tactics to use roadside bombs, the response should have been strategic, to ask to what extent our troops' presence was part of the problem, rather than tactical.

Mr Brown's attempt to justify our presence in Helmand as necessary to suppress al-Qa'ida-style terrorism at source is unconvincing and the British people are unconvinced. The Prime Minister elides Afghanistan and Pakistan. If international forces, including the British, withdrew to a limited role training the Afghan army and police, patrolling the Pakistan border and special forces operations, Afghanistan would not become a base for al-Qa'ida again.

The campaign to staunch terrorism at source should focus instead on Pakistan and global intelligence. The murders of 9/11 were plotted in Hamburg; those of 7/7 in unremarkable parts of urban Britain.

The British electorate does not accept the consensus of the Westminster establishment. Our ComRes opinion poll today shows that 77 per cent of the voters support this newspaper's position against that of the three main parties. And a clear majority believes that the presence of our troops in Afghanistan increases rather than diminishes the threat of terrorism on British streets.

While the main parties agree in their support for the war in Afghanistan, it will be hard to raise these strategic questions, but it is vitally important for the health of our democracy that they are raised.

Issues such as the deficit and Afghanistan may appear to make it harder to argue for our One of the Above campaign, which urges people to register (the deadline is Tuesday) and to use their vote. But the response to a three-party stitch-up, as on Afghanistan, should be to engage, argue and get involved, not to give up.

In this week's leaders' debate on foreign affairs on Thursday evening, Mr Clegg and David Cameron must set out their reasons for supporting the Government in this mission.