Mitt Romney came in peace. He said he wanted better education, more financial aid, gender equality and rule of law, and he was talking about the Middle East, not the Midwest. He even said he was consulting a group of "Arab scholars" sponsored by, of all things, the United Nations, to shape his plan for fixing the troubled region. "We can't kill our way out of this mess," he said.
And all his expressions of internationalism and support for women's liberation overseas made President Obama, by contrast, almost sound like a Republican hard-liner.
"Well, my first job as commander in chief, Bob, is to keep the American people safe," President Obama told the evening's moderator, Bob Schieffer.
Monday night's debate provided an odd role reversal that made Mr. Romney seem on the defensive, particularly because he at times stuttered and sputtered in his haste to make his points. He pronounced foreign names and countries correctly, but also carefully, worried perhaps that a mispronunciation would sink his credibility. Usually, it is Mr. Obama who seems professorial and long-winded. There were long moments when Mr. Romney made the president sound succinct and sharp-edged.
Perhaps trying to demonstrate the breadth of his knowledge, Mr. Romney careened from Iran to Poland to China to Latin America to Greece to balanced budgets. He delivered a long lecture on the strategic importance of Pakistan that was the same as Mr. Obama's position, then later complained, in detail, about spending cuts to the Navy.
"Well, Governor, we also have fewer horses and bayonets," Mr. Obama said, eliciting a laugh from the audience that echoed on Twitter, "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."
Mr. Romney tried a few jokes of his own, beginning the night with a crack that sounded more like a confession of jitters than good humor. Citing their recent exchange of jokes at the annual Al Smith dinner last week, Mr. Romney noted: "We were together at a humorous event a little earlier, and it's nice to maybe be funny this time not on purpose. We'll see what happens."
What happened wasn't particularly funny, but it was startling. Mr. Romney kept talking about American "strength" and the need to be "tougher," but he seemed at times unnerved by the president, a man he accused of being too weak.
When Mr. Romney complained about what he described as Mr. Obama's "apology tour" on his first overseas trip, he accused the president of snubbing Jerusalem. "And by the way, they noticed that you skipped Israel," Mr. Romney said.
Mr. Obama, finally comfortable with the fact that debates require confrontation, replied sharply: "When I went to Israel as a candidate, I didn't take donors, I didn't attend fund-raisers, I went to Yad Vashem, the — the Holocaust museum there, to remind myself the — the nature of evil and why our bond with Israel will be unbreakable."
(Read More: Romney Comments in Israel Outrage Palestinians)
Incumbency has its advantages in a foreign policy debate, but often inexperience can also be its own asset. Domestic policy focuses on what a candidate wants to do, be it raise taxes or cut them, reduce the deficit, invest in infrastructure, increase military spending, cut Medicare or save it.
But foreign policy is often presented as what the candidate will not do: add troops in Afghanistan, abandon Israel, start another war in the Middle East, negotiate with terrorists, put nuclear missiles in Europe.
Mr. Romney didn't really elaborate on Mr. Obama's mistakes and say what he would have done differently. Instead, he often highlighted where he agreed with the president. When asked by Mr. Schieffer if he regretted, in retrospect, calling for the fall of President Hosni Mubarak of Egypt, Mr. Obama said no. So, too, did his opponent.
"No, I believe, as the president indicated and said at the time, that I supported his — his action there. I felt that — I wish we'd have had a better vision of the future," Mr. Romney said.
"But once it exploded, I felt the same as the president did."