Recent days have seen new rumblings from anti-war activists against the war — not Iraq, where U.S. disengagement is well underway, but Afghanistan. One progressive commentator contends that the left has muzzled itself on Afghanistan for fear of undermining President Obama’s signature foreign policy initiative. Another says that Americans have just “zoned out”.

The real question is whether Afghanistan is just a lost cause, or put another way, whether Afghanistan has lived up to its billing as “the graveyard of empires”.

A year ago, I had a conversation with a leading member of President Obama’s “strategic review” task force. The group had been sent to Afghanistan to assess the prospects for strategic reform in turning around the crumbling Afghan effort. The recommendations of the group, later leaked as the McCrystal report, were for an Iraq-style “surge” in Afghanistan. After some resistance where he complained of being “boxed in” by overreaching military officers, President Obama embraced the recommendations of the task force in a speech at West Point.

Even before the President had made his decision, however, the leader in his task force described prospects in Afghanistan as bleak. He said we had a year, maybe 18 months, to produce real evidence of increased military control in key Afghan provinces and reductions in rampant corruption in Afghan leader Karzai’s government. Lacking those “metrics” showing progress, he predicted that support would collapse in Congress for sustaining the Afghan effort.

There is, at present, no evidence of a revolt in Congress. But support is clearly eroding among the President’s base among the chattering classes. The lack of evidence of progress, combined with dramatic escalations in the President’s domestic political troubles, is leading to a time when the U.S. will have to face the question of whether its longest war must come to a murky end with few permanent gains. The U.S. may have to abandon its nation-building project in Afghanistan sooner rather than later.

After that, the prospects for the future are even more uncertain. Without an Afghan base of operations (and with Kyrgyzstan now in peril as well), will the U.S. be able to sustain — militarily and politically — an effective ongoing campaign against al-Qaeda’s bases in Afghanistan and Pakistan? Will al-Qaeda be able to reclaim its lost ground and expand its appeal throughout the Muslim world by trumpeting a victory over the Americans?

When I asked him about what could happen after a U.S. failure in an Afghan “surge”, my source spoke darkly about a nuclear-armed Pakistan endangered by a resurgent Taliban-al-Qaeda axis. He viewed Pakistan, not Afghanistan, as the real stakes in the battle.

And the last line of defense may be crumbling.