Those of us who hoped for some kind of winding down of the longest war in US history will almost certainly be disappointed now. David Petraeus is the real Pope of counter-insurgency and if he decides that he needs more troops and more time and more resources in Afghanistan next year, who is going to be able to gainsay him? That's Thomas P. Barnett's shrewd assessment. Obama's pledge to start withdrawing troops in 2011 is now kaput. It won't happen. I doubt it will happen in a second term either. Once Washington has decided to occupy a country, it will occupy it for ever. We are still, remember, in Germany! But Afghanistan?

Obama's gamble on somehow turning the vast expanse of that ungovernable "nation" into a stable polity dedicated to fighting Jihadist terror is now as big as Bush's in Iraq - and as quixotic. It is also, in my view, as irrational, a deployment of resources and young lives that America cannot afford and that cannot succeed. It really is Vietnam - along with the crazier and crazier rationales for continuing it. But it is now re-starting in earnest ten years in, dwarfing Vietnam in scope and longevity.

One suspects there is simply no stopping this war machine, just as there is no stopping the entitlement and spending machine. Perhaps McChrystal would have tried to wind things up by next year - but his frustration was clearly fueled by the growing recognition that he could not do so unless he surrendered much of the country to the Taliban again. So now we have the real kool-aid drinker, Petraeus, who will refuse to concede the impossibility of success in Afghanistan just as he still retains the absurd notion that the surge in Iraq somehow worked in reconciling the sectarian divides that still prevent Iraq from having a working government. I find this doubling down in Afghanistan as Iraq itself threatens to spiral out of control the kind of reasoning that only Washington can approve of.

This much we also know: Obama will run for re-election with far more troops in Afghanistan than Bush ever had - and a war and occupation stretching for ever into the future, with no realistic chance of success. Make no mistake: this is an imperialism of self-defense, a commitment to civilize even the least tractable culture on earth because Americans are too afraid of the consequences of withdrawal. And its deepest irony is that continuing this struggle will actually increase and multiply the terror threats we face - as it becomes once again a recruitment tool for Jihadists the world over.

This is a war based on fear, premised on a contradiction, and doomed to carry on against reason and resources for the rest of our lives.

Maybe this is why you supported Obama - to see the folly of nation-building extended indefinitely to the least promising wastelands on earth, as the US heads toward late-imperial bankruptcy. It is not a betrayal as such. But it is, in my view, a huge and metastasizing mistake.

(Photo: Mark Wilson/Getty.)