As Army Secretary Pete Geren summed it up before the Senate Armed Services Committee on Tuesday, "Today we are an army long at war, in our seventh year in Afghanistan; next month, March, will be five years in Iraq. This is the third-longest war in American history, behind the Revolutionary War and the Vietnam War. And it is the longest war we've ever fought with an all-volunteer force." Both Geren and Casey said the army is badly stretched.

The debate between McCain and Obama—with Sen. Hillary Clinton on the sidelines for now—reflects serious behind-the-scenes tensions inside the military. In part because of the terrible strains on an army that has pushed its overseas deployments from the standard 12 months to a brutally long 15 months, Defense Secretary Robert Gates and senior Pentagon officials like Casey have been pressing to continue the drawdown in Iraq beyond the July cutoff date. That's when, under current plans, the United States will "pause" with 140,000 troops remaining there. (Petraeus announced last fall that he would withdraw five out of 20 Army brigades by July, reducing the U.S. presence from about 170,000 troops.)

But the Pentagon brass is also aware that the U.S.-led NATO forces in Afghanistan appear to be losing ground to the resurgent Taliban/Al Qaeda forces there—or at best holding them to a stalemate. That all but guarantees the extremists a "safe haven" from which to attack U.S. interests around the world. A senior U.S. official, in remarks this week, said NATO was now in an "existential" crisis over Afghanistan and that he hoped the French, of all people, would pull Washington out of the crisis with additional deployments. But French President Nicolas Sarkozy is hesitating over such a move, and U.S. commanders on the ground in Afghanistan say they need more troops now. In addition, Afghanistan may be descending into a political crisis that is almost as serious as Iraq's; President Hamid Karzai is weaker than ever, confined to Kabul, and increasingly resentful of Western interference.

Obama says that if elected he would deploy an additional two brigades to Afghanistan. Sen. Joe Biden, a former Democratic contender who is chairman of the Senate Foreign Relations Committee—and also a potential secretary of state in an Obama or Clinton administration—told reporters this week that on a recent visit to Afghanistan he was informed by the U.S. commander of the international force there that he needed another two brigades, or about 10,000 U.S. troops, to take back Helmand and other provinces now controlled by the Taliban. "But he said, 'But I can't get 10,000 troops'," Biden said. Casey told the Armed Services Committee he hasn't even examined whether keeping 15 brigades in Iraq and adding two to Afghanistan is feasible.

Dan Senor, the former spokesman for the U.S. occupation in Iraq who now talks with various Republican candidates, including McCain, says McCain has to take the Obama critique seriously and move beyond mocking his younger, less experienced adversary. "McCain does have to walk through this," Senor told me. "He has to frame the debate to say that no matter how bad Afghanistan gets, if Iraq goes nothing else matters. A failed state in Iraq at this point is a far greater threat to American security interests around the world and of far greater urgency than pre-empting a possible failed state again in Afghanistan. That's the reality." Perhaps it is, or maybe it isn't. If McCain and Obama are nominated, it's a point that is certainly going to be debated until the fall.

© 2008