At final debate, Obama’s foreign policy offers tempting targets. Can Romney hit them?

Questionable progress amid mounting casualties in Afghanistan. A bloody civil war in Syria. Escalating tensions with Russia. A freshly assertive China worrying its neighbors. Iran defiantly pursuing its nuclear program. The killing of the American ambassador to Libya. Mitt Romney will have his pick of targets Monday night at his third and final debate with President Barack Obama, a faceoff focused on world affairs.
It's not the top issue on many voters' minds (that would be the economy, of course). But aides to both campaigns say voters need to be comfortable with the idea of their preferred candidate representing the country overseas—and responding to a literal life-or-death crisis.
Romney's mission seems straightforward: Convince any doubting voters that he can handle foreign policy. But Romney comes into the debate effectively the underdog, and not just because he isn't the commander in chief. Some of his forays into world affairs have foundered on avoidable missteps that at times have left him looking as awkward on the world stage as a very small dog trying to bite a watermelon.
Obama joked Thursday about his rival's best-known foreign policy struggle: a trip this summer to Britain, Israel and Poland that helped raised Romney's profile but was marred by headlines about gaffes.
"World affairs are a challenge for every candidate," Obama said at the Alfred E. Smith charity dinner in New York. "Some of you guys remember, after my foreign trip in 2008, I was attacked as a celebrity because I was so popular with our allies overseas. And I have to say, I'm impressed with how well Gov. Romney has avoided that problem."
At the debate, Obama plans to employ a strategy that calls for trying to make Romney look like a risky bet, while emphasizing his own successes (as Obama joked at the dinner: "Spoiler alert: We got bin Laden").
But you can cut out the smug chuckling, Obama fans: The political firestorm over the Sept. 11 attack in Benghazi, Libya, which claimed the lives of Ambassador Chris Stevens and three other Americans, has come as the president's poll numbers on foreign policy have slumped. An NBC/Wall Street Journal survey released Sunday found that 49 percent of registered voters approved of Obama's handling of world affairs—the same as one month ago, but down from 54 percent approval and 40 percent disapproval in August. And the president's lead over Romney on who would make a better commander in chief slipped: He was up 44 percent to 41 percent compared to 47 percent to 39 percent one month ago.
And Obama isn't always sure-footed: Republicans, led by Romney, have hammered him for describing the bloody unrest in the Middle East as "bumps in the road" to democracy, for example. And the president earlier this year apologized to Poland's president after he referred to a "Polish death camp" that was on Polish soil but was built and operated by the German Nazis.
Against this backdrop, some foreign policy analysts have suggested that the two candidates differ mostly in symbol, not substance, when it comes to foreign affairs. There is some truth to this: On certain key issues, they don't disagree nearly as much as one, or both, of the candidates insist that they do. And when challengers become incumbents they often (re)discover the value of pragmatism. But on a handful of issues, a Romney administration could look sharply different from an Obama second term. Either way, here are some of the likely fights we'll see on Monday night.
Iran's nuclear program
Obama and Romney agree on the need for tough economic sanctions, backed with the threat of military force, to keep Tehran from developing a nuclear weapon. But each has a different "red line"—the point at which he would be willing to take the country to war.
The key distinction: Obama says Iran cannot be allowed to build a nuclear weapon—and insists that the United States and its allies will know if it tries to put one together, and will act to prevent it. Romney says Iran cannot be allowed to have the capability to build a nuclear weapon.
Romney's position is in line with that of Israeli Prime Minister Benjamin Netanyahu, who has repeatedly pressed the Obama administration to take a harder approach with Iran. It also sets a lower threshold for military action. Romney says he favors tougher sanctions than the ones Obama has approved, and insists that the president's threats to go to war as a last resort haven't been credible.