John McCain made the central argument for his campaign yesterday, bragging that “I know how to win wars.” But his boast did not respond to the central charge from Obama’s speech (paraphrasing):

McCain and Bush fought the wrong war, and fighting an unnecessary war in Iraq hurt our military, our economy and our security. We have to end that war to get our priorities straight.

If the election were decided on security issues, it would likely turn on which of those two statements voters find more compelling.

We owe this clarity to Admiral Mullen, who recently confirmed that deteriorating conditions in Afghanistan and Pakistan cannot be reversed as long as US forces are tied down in Iraq. Mullen’s candor thus forced McCain to deal with the issue he and Bush have dodged for five years and which Obama has been emphasizing: there is a strategic choice to make between Iraq and Afghanistan, because we don’t have the resources to do both at once. A President's main job is to make good strategic choices, not just to be Commander in Chief.

From Obama's speech:

What’s missing in our debate about Iraq, what has been missing since before the war began, is a discussion of the strategic consequences of Iraq and its dominance of our foreign policy. This war distracts us from every threat that we face and so many opportunities we could seize. This war diminishes our security, our standing in the world, our military, our economy, and the resources that we need to confront the challenges of the 21st century. By any measure, our single-minded and open-ended focus on Iraq is not a sound strategy for keeping America safe. . . .

In the 18 months since the surge began, the strain on our military has increased, our troops and their families have borne an enormous burden, and American taxpayers have spent another $200 billion in Iraq. That’s over $10 billion each month. That is a consequence of our current strategy.

In the 18 months since the surge began, the situation in Afghanistan has deteriorated. June was our highest casualty month of the war. The Taliban has been on the offensive, even launching a brazen attack on one of our bases. Al Qaeda has a growing sanctuary in Pakistan. That is a consequence of our current strategy.
. . .

So let’s be clear. Senator McCain would have our troops continue to fight tour after tour of duty, and our taxpayers keep spending $10 billion a month indefinitely; I want Iraqis to take responsibility for their own future, and to reach the political accommodation necessary for long-term stability. That’s victory. That’s success. That’s what’s best for Iraq, that’s what’s best for America, and that’s why I will end this war as President.

McCain must now explain how he can justify and sustain a huge occupation of Iraq and prove he can simultaneously "win" in Afghanistan. The additional surge troops now returned from Iraq are not available for immediate duty elsewhere, and there aren’t other replacements available. McCain waffed yesterday on whether additional troops for Afghanistan would be provided by NATO allies or the US. [updated link; and Gates says it may be US troops. ]

McCain claims he can win both wars by applying Petreaus’ counter-insurgency tactics in Afghanistan. I suspect our commanders there think that’s what they’ve been doing. But the problem, McCain explained, is the lack of a unified command over US and NATO forces, and the unwillingness of some NATO countries to accept US rules of engagement.

How will McCain convince NATO to provide more troops under an unfettered US command? The Bush Administration has mostly failed to get more NATO troops even under the current arrangements, which our allies apparently prefer. And why would NATO be more likely to cooperate with a President whose views of “victory” are defined by unlimited war and occupations that last a hundred years?

Juan Cole has some sober questions for both candidates about the value of additional US troops in Afghanistan.