In the current circumstances of the failure of the opium strategy, the bloody fighting in Helmand, the row inside Nato and the argument about Paddy Ashdown's unacceptability to Hamid Karzai, the Afghan President, much of this pessimism seems appropriate. But if we are to follow its dictates, its proponents should do a better job of spelling out what it means. Anyone who still favours a military presence is easily decorated with the order of the armchair commentator, but let us see what other commentators are prepared to sit through.
Canada has already threatened to pull out its troops from Kandahar province in a year's time if other Nato countries don't contribute more. We must assume that if Britain were to begin to talk about a draw-down, then Canada would carry out this threat. British forces would then be exposed in Helmand and, presumably, would also withdraw. Let us suppose that an angry and abandoned US follows the "lead" offered by its allies, and itself pulls out, leaving itself only an air-to-ground interdiction capability.
Here are the likely consequences of such a pattern. The Afghan Government would collapse, to be replaced by an overt civil war fought between the Taleban and local governors in the various provinces. A million or more Afghan refugees would again flee their country, many of them ending up in the West. Deprived of support from the US, as recommended by our commentators, President Musharraf or a successor would effectively withdraw from the border regions, leaving a vast lawless area from central Afghanistan to north central Pakistan. Al-Qaeda and other jihadists would operate from these areas as they did before 9/11. This time these forces - already capable of assassinating a popular democratic politician - would seriously impact upon the stability of Pakistan, which is a nuclear state.
Jihadists everywhere, from Indonesia to Palestine, would see this as a huge victory, democrats and moderates as a catastrophic defeat. There would hardly be a country, from Morocco to Malaysia, that wouldn't feel the impact of the reverse. That's before we calculate the cost to women and girls of no longer being educated or allowed medical treatment. And would there be less terror as a result?
No, there wouldn't. The fainthearts who think the War on Terror can be ducked need to understand that the nature of the game has changed. Afghanistan is essentially a single front in a global conflict. The ramifications of retreat (i.e. defeat) in Afghanistan will be global, from Teheran to Gaza, from Pyongyang to Caracas, the failure of Western resolve will render the world a far more dangerous place even than it is now. For all its faults, the current government of Afghanistan must be supported, and the Taleban neutralised. However bad things are now, they could be far worse.