At some point, if one accepts the premise that victory against the Taliban is unachievable, negotiation must be an option. This article by James Fergusson, now over a year old (15 Jun 08) is of interest:

"The return of the British Army for the fourth time since the 1830s baffled the mullah, despite my protestations that the British wanted to help secure economic development.

'You British are clever people,' he said. 't makes no sense.... A clever man does not get bitten by a snake from the same hole twice.' 'Of course,' said the mullah, if we had come unarmed, 'you would have been our guests, just as you are our guest now. If your engineers and agriculture experts had come to us and explained what they were trying to do, we would have protected them with our lives'

...... it is time, surely, to start talking seriously to the Taliban. In any case, a negotiated settlement is the likeliest outcome of the struggle, as senior Army officers know full well. 'The ultimate legacy will be a government in Afghanistan, in X years' time, with Taliban representation,' said Brigadier Ed Butler, one of Carleton-Smith's predecessors in Helmand, who announced his resignation a week ago. Historically, there are very few insurgencies that have not ended in negotiation; and even President Karzai – who, let it be remembered, supported the Taliban in the regime's earliest days – is in favour of reconciliation with the movement's more biddable elements.

Negotiating with the Taliban is, of course, not something Western liberals would choose to do, but it is surely the lesser of two evils: a realpolitik solution rather than a totally impractical 'ethical' one. The Taliban will never be 'defeated' in the conventional sense. The alternative to dialogue is go on with the war, in which case many more young British soldiers will die, perhaps for nothing. Our strategy will have to change direction. The sooner it does so the better."

IMO ativities in Anbar in Iraq proved (not conclusively) that bringing some insurgents into the tent must be a part of the process whether concurrently or sequentially. Arguably the same could be said of Northern Ireland. Critical issue is if you can get dialogue at the same time as upping the kinetic tempo - certainly In Basra in 06/07 it did seem to speed participants to the table; especially if done in tandem with a stiffening of host nation security forces' resolve.