General Omar Bradley famously condemned a plan to extend the Korean conflict into China as “the wrong war, at the wrong place, at the wrong time and with the wrong enemy”. Afghanistan, by contrast, is precisely the right war in the right place at the right time and with the right enemy. The struggle is fundamental not only to the fate of that nation itself but the turbulent region in which it is placed and wider international order. It has also become the absolute test case of the credibility of Nato and through this the ability of Britain to exercise its authority and its influence overseas. It is a battle that has to be won. Yet more through institutional incoherence than any other factor there is the real risk that it will be lost by default. This is not a case of classic “mission creep” (too many objectives) but emerging “mission seep” (no sense of an objective at all).

The problem is not that Nato has an insufficient presence inside Afghanistan. It is instead that far too many of these military contingents have been sent there for symbolic reasons and come with so many restrictions on their activities that they are effectively useless for the fight in hand. The burden has been placed, wholly disproportionately, upon Britain in Helmand province, Canada in and around Kandahar (where heavy losses have been sustained) and the US, which is operating with some success in the east of the country. Ottawa has made it plain that it will not tolerate this arrangement indefinitely and if a fairer formula is not found will start to evacuate. If this were to occur, then others would follow. As Robert Gates, the US Defence Secretary, has correctly cautioned, Europe is in danger of inflicting massive damage on Nato by its inactivity.

These matters are supposed to be debated and resolved at a Nato summit in Bucharest in April. A new approach can wait that long. If the situation is to be rescued, as it can be, then a three-pronged approach must be adopted.

The first involves what might be described as a “political surge” - a serious commitment to victory akin to that which the US undertook in Iraq under General David Petraeus - not only within Nato itself but by making the case for a sustained military involvement in Afghanistan to domestic opinion. In Britain, this is an enormous test for Gordon Brown, David Miliband and Des Browne who have, at times, offered the impression that this is a war which they would rather wage discreetly. A political surge has to lead to a military one. All Nato members have to empower their troops to participate as forcefully as the US, Britain and Canada. If, even then, insufficient progress is recorded, additional troops from across the board should be brought in. The hint from Nicolas Sarkozy that France will enhance its efforts in Afghanistan is especially welcome.

A political and a military surge also has to be supplemented by a coherent economic policy. The coalition approach towards the poppy fields, in particular, is an inconsistent shambles. In some places, money is being paid directly to farmers to alter tack, but elsewhere funds have been dispatched to Kabul - from where they disappear. There has to be one strategy that reflects the reality on the ground.

If Nato pulls together, it should be more than capable of crushing the Taleban and engaging in modest but worthwhile reconstruction. If it fails in that task, then not only will Afghanistan (and Pakistan and beyond) be the worse for this, an organisation that has accomplished so much will, alas, have rendered itself functionally redundant.