The third and final debate fell handedly to President Barack Obama. On five of the six main talking points, Romney agreed almost entirely with the President, which did not help him distinguish himself further. Romney went on the attack strongest when he could tie into economic issues, where he is clearly more comfortable. He showed an incompetency in understanding U.S. military and its relation to the budget and spending for the Navy and seemed reckless in his assertions about how he would pay for his proposed military spending.
Romney noticeably changed his position on removing troops from Afganistan, he changed his mind on troop withdraws by 2014 being up to the generals in the field, and said that they would definitely be out by 2014.
However, it is quite possible that Romney's campaign planned all along to simply agree with the President and try to attack him on domestic issues when possible, because that has helped him close his gap on the President and are issues where he has the greatest experience. For example, he is one of a few Republicans to hear agree with the President that the surge worked. The public widely agrees with or does not understand the Obama administration's foreign policy, so it was safe territory to agree.
Ultimately, domestic issues will decide this election as economic issues are closest to the undecided voters. Obama proved his superiority on foreign affairs, but only gained marginal ground when he attacked Romney for his indecisiveness on foreign policy, his change in opinions, and misunderstanding of military spending.
For real-time analysis of the presidential debate, see here.