If you're in a hole stop digging. Denis Healey's admonition to politicians has been so often quoted that it's become almost a cliché. But it's nonetheless true for all that. And nowhere is it more so than in Afghanistan.
The successive delays in the announcement of President Obama's much vaunted statement of US policy towards the Afghan venture has been treated as yet another example of the fumbling that has become something of a feature of the new administration, in foreign policy as much as home economics. It shouldn't be. Obama's reconsideration of his approach to Afghanistan, together with his policy towards Pakistan, is one of the best things that has happened since he gained office.
Obama came in committed to ramping up the US military effort there as the counterbalance to his determination to get the US troops out of Iraq. Afghanistan was the one area of policy where the new President was prepared to follow his predecessor. How far Obama genuinely believed this vision of a battle-to-the-death may be doubted. Since then he's steadily retreated from that stance on taking office and listening to the advice of his new Special Envoy to the region, Richard Holbrooke, as well as the urgings of the generals and the hesitations of the State Department.
The turn-around in the White House approach has been truly astonishing. Where once the talk had been all about a General Petraeus-dictated surge that would see expanded US forces seize the strategic high ground, now all the talk is of the need to rebalance programmes from the military to civil assistance. In place of the accusations of sloth and even cowardice among America's allies, now the talk is less of demanding more troops from Europe than more help with policing, transport and energy.
Instead of talking of the battle in Afghanistan, Holbrooke has returned from his first trip announcing that the US now recognised that the situation in that country could not be divorced from the deteriorating conditions in next door Pakistan. Where initially the Taliban had been rolled up with al-Qa'ida in a ball called the "enemy", in the last few weeks there has been open discussion of negotiating with so-called "moderate" Taliban.
Most astonishing of all, President Obama, having declared "no, the US is not winning the war", has even been brave enough to speak out the dreaded "e" word, saying that the US had to consider an exit strategy among its objectives.
What accounts for this change of tack by the US administration - and has certainly caused Richard Holbrooke to tell some harsh truths in the Oval office after his recent visit - is the gradual dawning of the realisation in the White House that Afghanistan is a real mess and quite possibly one that has no solution as far as the West is concerned.
It's easy for General Petraeus and his supporters in Washington to talk of the Iraqi example and to argue that, with one more push, the war can be won. But Afghanistan isn't Iraq. There the US was eventually able to use the Shia-Sunni divides and the growing unpopularity of al-Qa'ida's civilian atrocities to split the Sunni tribal leaders from the foreign terror groups, persuade them to join the fight on the US side and to convince the Shia radicals that a cease-fire was in their interests. The government of Prime Minister al-Maliki proved, somewhat unexpectedly, to have more guts and power than they'd given it credit it for.
In Afghanistan, in contrast, the US forces did not win a clear victory. Rather they, and in particular the air force, enabled the Northern Alliance to march into the Taliban-controlled cities as conquerors, and for the war lords to claim local control as their reward. President Karzai has never been more than a figurehead. That was the reason he was accepted by all parties in the first place.
The geography of the country obviates central control and favours the guerrilla fighter. The presence of a foreign "occupying" force makes it an easy challenge for the unemployed youth. The conjunction of an anti-drugs policy intended to root out poppy growing with a military exercise aimed at wiping out insurgents has fatally sullied both aims. Add to that a porous border which allows the rebels to rearm, regroup and run away and you have all the classic conditions of a war that is basically unwinnable.
Talk to most British military and they know this. Speak to ministers and politicians in this country and they are in total denial. Speak now to officials and experts in Washington, in contrast, and the truth is at last being debated out loud. The difficulty is how to get out of the quagmire.
Almost everything that the allies are doing is making things worse. The more you talk of beefing up Nato, the more it appears as a Western, white force intent on suppressing an indigenous population and the worse the division within what was once the world's greatest military alliance open up. The more you use drones and air strikes to hit across the border, the greater the local resentment. Try to put backbone into Karzai by insisting that he appoint a strong Prime Minister of your choice - as Washington is now - and you simply unbalance further the confused politics of a fractioned country. Put pressure on the Pakistan government to take control of its tribal areas and you only tag the new president there with the sobriquet of the lapdog of overweening America.
Ultimately there is no future in Afghanistan other than the exit door, any more than there is a chance for the politics of Pakistan or Afghanistan to develop other than through a Western declaration of non-interference. Whether US politics would accept such a step at the moment is doubtful. Listen to Holbrooke and you hear all the old empty talk of forcing the government of Kabul and Islamabad to exercise more central control and calling the Taliban "outriders for al-Qa'ida" as if they were one and the same thing (which they aren't).
All one can say as the world awaits the US President's Afghan plan, before the meeting of interested parties called by Mrs Clinton in the Hague on Monday and the Nato summit in a fortnight's time, is that Obama seems ready to stop digging. And that, at least, is a start.