On Syria, Romney protested he would not intervene militarily as President. On Iran, described as the single most important threat to America, he insisted that military force would be a last resort. On Afghanistan, he stressed that all American soldiers would be out by the end of 2014. He congratulated Obama on the killing of Osama bin Laden, although adding that the Administration lacked a comprehensive strategy for dealing with Islamic jihadists.
Again, a putdown from the professor. "I'm glad that you agree that we have been successful in going after al Qaeda," said Obama. The Romney strategy, however had previously been "all over the map and is not designed to keep Americans safe or to build on the opportunities that exist in the Middle East". Obama then moved into flip-flop territory, Romney's most vulnerable area in the campaign. "Every time you've offered an opinion you've been wrong," Obama said, referring to Romney's earlier assertion that the number one threat to America came from Russia.
A sitting president will always hold an advantage over a challenger in a foreign policy debate. But Romney also failed to press the President on Libya despite the Administration still having questions to answer about the circumstances of the killing of Ambassador Chris Stevens in a terrorist attack on the US consulate in Benghazi.
Obama was expecting to be attacked over his poor relations with Prime Minister Benjamin Netanyahu. So he pre-emptively referred to the Administration's consultations with Israel on Syria, and noted the "unprecedented" military and intelligence co-operation, including on Iran. "If Israel is attacked, America will stand with Israel," Obama said. It was left to Romney to repeat: "I want to underscore the same point the President made which is that if I'm President of the United States, when I'm President of the United States, we will stand with Israel."
This last debate mattered because with the presidential race in a dead heat, even a discussion of foreign policy provides an opportunity to influence undecided voters.
Yet the candidates were aware that foreign policy is not the main issue on which the campaign is being fought. After they strayed on to plans for economic recovery in America 35 minutes into the 90-minute debate in Florida, moderator Bob Schieffer of CBS news was left bleating: "Let me get back to foreign policy."
As the debate wandered back to education, Romney warned Obama his plans to hire teachers would not be enough to grow the economy, although he was careful to add: "I love teachers." "We all love teachers," said Schieffer.
It was quite a night for the teacher-in-chief.
The debate
Barack Obama's best lines:
"Governor, when it comes to our foreign policy, you seem to want to import the foreign policies of the 1980s, just like the social policies of the 1950s and the economic policies of the 1920s."
"We also have fewer horses and bayonets because the nature of our military has changed. We have these things called aircraft carriers where planes land on them."
"Every time you've offered an opinion you've been wrong."
Mitt Romney's best lines:
"Attacking me is not an agenda."
"We can't kill our way out of this mess ... We must have a comprehensive and robust strategy."
"We're four years closer to a nuclear Iran."
"That does not mean they [China] can just roll all over us and take our jobs."
Gaffes: A geographically challenged Romney said: "Syria is Iran's only ally in the Arab world. It's their route to the sea." Moderator Bob Schieffer referred to the former al-Qaeda leader as "Obama's bin Laden".
Expert view: Dotty Lynch, professor of public communication at American University: "By agreeing on the big points of foreign policy, Romney played it safe tonight, and tried to move the conversation to the economy where he thinks he's stronger."
Debate snap polls
CBS: Obama 53 per cent, Romney 23 per cent, Tie 24 per cent
CNN: Obama 48 per cent, Romney 40 per cent
Latest national polls
Politico: Obama 47 per cent, Romney 49 per cent
CBS: Obama 48 per cent, Romney 46 per cent
ABC/Wash Post: Obama 49 per cent, Romney 48 per cent
Wash Times: Obama 50 per cent, Romney 47 per cent
Monmouth: Obama 45 per cent, Romney 48 per cent
Gallup: Obama 45 per cent, Romney 51 per cent
Rasmussen: Obama 47 per cent, Romney 49 per cent
IBD/Tipp: Obama 47 per cent, Romney 43 per cent