There is also the small matter that the date of the planned 2014 withdrawal of U.S. combat troops has been negotiated and agreed to not only by the Afghan government, but also by NATO allies and the more than 40 countries with some kind of presence in Afghanistan.
For his part, during the debate Obama did not mention the Strategic Partnership Agreement that his administration has spent considerable effort in negotiating with Afghanistan that would keep some as-yet-unspecified number of American troops in an advisory role in Afghanistan up until 2024.
Whoever is in the Oval Office next year is scheduled to complete the negotiations of this long-term agreement with the Afghan government. It will spell out in detail the roles and numbers of what will likely be many thousands of American troops who could remain in Afghanistan for a decade beyond 2014.
This fact went unmentioned in Monday's debate because few Americans have any appetite left for the Afghan intervention.
Where there was major disagreement was on defense spending, which the Romney campaign says should not be cut. Romney cited a factoid that he has used before on the campaign trail, which is that the U.S. Navy today is supposedly smaller than it was in 1917.
This set up Obama for some of his best lines of the night: "Well, Governor, we also have fewer horses and bayonets, because the nature of our military's changed. We have these things called aircraft carriers, where planes land on them. We have these ships that go underwater, nuclear submarines."
This served implicitly to make a larger point, which is that other than some vague gauzy rhetoric about the need for America to be stronger, Romney has never really articulated a strategy distinct from Obama's that would necessitate the larger military that he is calling for.
In any event, the notion that the U.S. is falling behind militarily is laughable. Last year the U.S. spent more on defense than the 13 countries with the next highest defense budgets combined.