WASHINGTON (AP) -- For months, the one reliable constant for President Barack Obama was the public's approval of his handling of foreign policy and terrorism. Al-Qaida was on the run, he would say. The war in Iraq was over. Bin Laden was dead. Crowds cheered, and national polls showed a majority in the country stood with him.

But with two weeks left before Election Day, the landscape has changed. As Obama and Republican rival Mitt Romney talk foreign policy in their final debate Monday night in Boca Raton, the president is facing headwinds from abroad.

Libya. Uncertainty in a post-Arab Spring world. Iran's nuclear intentions. U.S. casualties at the hands of Afghan security forces. Europe's continued struggles with its economic and financi

Romney, who is far less experienced on foreign policy, is seeking to close the deal with voters. He'll use Monday's debate to portray himself not only as an economic savior but as a plausible and stronger commander in chief.

Obama will warn that Romney represents the kind of foreign policy "that gets us into wars with no plan to get out."

The debate will pick up where the second debate left off -- on the Sept. 11 attack on the U.S. Consulate in Benghazi, Libya, that killed four Americans, including Ambassador Chris Stevens. The attack underscored the uncertainty that has engulfed parts of the Muslim world after the Arab Spring uprisings that Obama supported. Obama faces difficult questions about his administration's accounts of the Benghazi attack and over unheeded requests for additional security in Libya's diplomatic outposts.

The debate also unfolds amid fresh reports that the Obama administration is holding open the possibility of one-on-one negotiations with Iran over its nuclear program -- a hardly certain development in what has been the most diffcult national security problem confronting the U.S.

The possible Iranian talks, first reported by The New York Times on Saturday, introduce a surprise element into the election campaign and provide a counterpoint to Romney's argument that Obama has not done enough to protect Israel against an Iranian nuclear threat. The White House denied that an agreement to hold talks was in place.

Moderator Bob Schieffer of CBS News has picked five topics for Monday's debate, devoting the most time to the Middle East and terrorism. Other subjects are America's role in the world, Afghanistan and Pakistan, Israel and Iran, and the rise of China.

Unlike their sharp divisions on economic and social issues, the foreign policy quarrels between Obama and Romney are less about goals than about strategy. Both candidates want to end combat troop presence in Afghanistan in 2014, but Romney says such a step should not be hasty. Romney backs Obama administration sanctions against Iran but says Obama's military threats should be tougher. Both stand tough against China on trade, but Romney would label China a currency manipulator and consider imposing tariffs to protect U.S. manufacturers. Both say the U.S. should not send U.S. troops to strife-torn Syria, but Romney has called for "more assertive" tactics.

Voters want to see strength in their leaders, and Obama can't afford to be defensive. But the country is also war weary, and Romney can't sound too aggressive.

Though the days of Obama winning a Nobel Peace Prize seem forgotten after euro crises, Arab Spring and Middle East tumult, his standing on the world stage had seemed solid compared to Romney, who faltered on a summer trip overseas to the UK, Israel and Poland. He slighted the British over security preparations for the Olympics and angered Palestinians by crediting Israel's culture for its greater economic success in the region.

Romney's ratings on foreign policy among U.S. voters, however, have been improving at Obama's expense. Obama's approval on foreign policy issues last month fell below 50 percent for the first time since May 2011, according to an NBC News/Wall Street Journal poll. And a Pew Research Center poll earlier this month found Obama and Romney almost even in public perceptions of who would better handle foreign policy questions. Romney had trailed Obama by 15 points on the same question in September.

Still, Obama is counting on one accomplishment that even Romney concedes.

Obama reminded the audience at a charity dinner last week that the last debate would focus on foreign policy. "Spoiler alert," he added. "We got bin Laden."