US President Barack Obama and his Republican challenger Mitt Romney have battled over national security in the third and final presidential debate.
US President Barack Obama has forcefully attacked his Republican challenger Mitt Romney, in their third and final presidential debate.
The rivals tangled over the Arab Spring, Iran, China's rise and more in a feisty 90-minute head-to-head.
During the tense encounter in Florida, the rivals tangled over the Arab Spring, Iran, Israel and China.
Mr Obama said his challenger was "all over the map" on foreign policy, while Mr Romney said the president had failed to uphold American global leadership.
Mr Obama said his rival was "all over the map" on foreign policy. But Mr Romney said the president had allowed "chaos" to engulf the Middle East.
The two candidates are running neck and neck with two weeks until the election.
Two instant polls said Mr Obama won the head to head.
'Al-Qaeda rushes in'
'Rising tide of chaos'
In the debate at Boca Raton, Florida, moderated by veteran CBS News presenter Bob Schieffer, there were no noticeable gaffes or knockout blows.
The Democratic president went on the attack from the start of Monday night's forum, trying to trip up his rival.
The forum at Lynn University featured little of the interrupting that marked their second encounter last week in New York, when Mr Obama came out swinging after his lacklustre performance in their first head to head in Denver, Colorado.
But analysts say Mr Obama did not land any knockout blows on Mr Romney, who has been gathering momentum with two weeks to go until election day, in a race that is now neck and neck.
The rivals found some common ground - each declared unequivocal support for Israel and both voiced opposition to US military involvement in Syria.
The debate at Lynn University in Boca Raton, which was moderated by veteran CBS News presenter Bob Schieffer, was not as fractious as their second encounter last week, when Mr Obama came out fighting after his lethargic performance in their first meeting.
Mr Romney also said he agreed with the president's policy of withdrawing troops from Afghanistan by 2014 - the Republican has suggested otherwise in the past.
But there were several scathing exchanges, with the president seeking to portray his challenger as a foreign policy novice who lacked the consistency to be commander-in-chief.
In laying out one of his overarching themes on foreign policy, Romney said the US under President Obama's leadership had allowed "tumult" to engulf the Middle East.
Mr Obama said the former Massachusetts governor had backed a continued troop presence in Iraq, opposed nuclear treaties with Russia and flip-flopped over when the US should leave Afghanistan.
He cited civilian deaths in Syria, the rise of al-Qaeda affiliates in North Africa and Iran's nuclear programme.
"What we need to do with respect to the Middle East is strong, steady leadership, not wrong and reckless leadership that is all over the map," said Mr Obama.
But the Republican steered clear of his suggestion in the last debate that the Obama administration had mishandled last month's Libya US consulate attack, which left four Americans dead.
But Mr Romney charged that the president had allowed a "rising tide of chaos" to sweep the Middle East, giving al-Qaeda the chance to take advantage.
"What's been happening over the last couple of years is, as we're watching this tumult in the Middle East, this rising tide of chaos occur, you see al-Qaeda rushing in, you see other jihadist groups rushing in," Mr Romney said.
"I congratulate him on taking out Osama Bin Laden and taking on the leadership of al-Qaeda," said Mr Romney, "but we can't kill our way out of this. We must have a comprehensive strategy."
"I congratulate him on taking out Osama Bin Laden and taking on the leadership of al-Qaeda, but we can't kill our way out of this... We must have a comprehensive strategy."
Mr Obama hit back sarcastically that he was glad Mr Romney had recognised the threat posed by al-Qaeda, reminding him that he had previously cast Russia as the number one geopolitical foe of the US.
Mr Obama hit back that he was glad that Mr Romney had recognised the threat posed by al-Qaeda, reminding the former Massachusetts governor that he had earlier this year cast Russia as America's number one geo-political foe.
"I know you haven't been in a position to actually execute foreign policy," said Mr Obama, "but every time you've offered an opinion you've been wrong."
The president sought to portray Mr Romney as a foreign policy novice who lacked the consistency needed to be commander-in-chief.
Mr Romney, whose tone during the debate was measured, described a trip by President Obama to the Middle East as an "apology tour" that had projected American "weakness" to enemies, while bypassing close ally Israel. Mr Obama called that claim the "biggest whopper" of the campaign.
'Strong, steady leadership'
Mr Romney also said: "We're four years closer to a nuclear Iran", although he appeared to soften the uncompromising tone that has been the hallmark of his campaign by emphasising that military action should be a last resort.
Mr Obama said Mr Romney had backed a continued troop presence in Iraq, opposed nuclear treaties with Russia, even when they had broad bipartisan backing, and accused the Republican of flip-flopping over whether the US should have a timeline for leaving Afghanistan.
"What we need to do with respect to the Middle East is strong, steady leadership, not wrong and reckless leadership that is all over the map," Mr Obama said.
The president said that he had ended the war in Iraq and "decimated" al-Qaeda's leadership, allowing the US to prepare a responsible timeline for withdrawing from Afghanistan.
Mr Romney, whose book is called No Apology, accused Mr Obama of having gone on "an apology tour" after he took office and of saying at the time he would meet "all the world's worst actors", including leaders from North Korea and Iran.
"I think they looked at that and saw weakness," Mr Romney said.
The president hit back, saying: "Nothing Governor Romney has just said is true, starting with the notion of me apologising," a claim Mr Obama labelled the "biggest whopper" of the campaign.
The rivals also jostled to act tougher than the other on China, as allegations flew about trade violations and currency manipulation by Beijing.
'Fewer horses and bayonets'
'Fewer horses and bayonets'
Although the debate's focus was meant to be on foreign affairs, the two candidates pivoted repeatedly back to the fragile US economy, the issue uppermost in voters' minds.
The rivals found plenty to agree on - declaring unequivocal support for Israel, voicing opposition to US military intervention in Syria, and insisting that China play by the rules in trade.
Mr Romney said he knew what it took to create jobs and boost pay, while Mr Obama was nine million jobs short of his pledge of 5.4% employment.
Mr Romney also backed the president's policy of withdrawing from Afghanistan by 2014 - something the Republican has previously disagreed with.
But Mr Obama accused Mr Romney of planning $5 trillion of tax cuts and $2 trillion of defence spending the military had not even requested.
Mr Romney barely touched on last month's deadly assault on the US consulate. The Republican's line of attack on that subject in the last debate was widely perceived to have misfired.
"You mentioned the Navy, for example, and that we have fewer ships than we did in 1916," Mr Obama said in one of the night's most memorable lines.
In one of the most biting exchanges, Mr Obama mocked Mr Romney's complaint that the US had fewer ships now than it did during World War I.
"Well, governor, we also have fewer horses and bayonets, because the nature of our military's changed."
"You mentioned the Navy, for example," said Mr Obama, "and that we have fewer ships than we did in 1916. Well, governor, we also have fewer horses and bayonets than we did in 1916."
Although the debate was meant to focus on foreign policy, the two candidates repeatedly pivoted back to the fragile US economy, the issue uppermost in American voters' minds.
A lacklustre performance by Mr Obama in the opening debate in Denver, Colorado, on 3 October gave Mr Romney a campaign boost.
But in their second face-off in New York last week, a more aggressive Mr Obama buried the memory of a poor first showing as he came out swinging on the economy, tax and foreign policy.
After Monday night's showdown, both candidates will be returning to the campaign trail for a gruelling final two weeks of wooing voters in swing states.
The final debate behind them, both men will now launch a final two weeks of campaigning in swing states.
The final debate behind them, both men will now launch a final fortnight of campaigning. Already four million ballots have been cast in early voting in more than two dozen states.
Already four million ballots have been cast in early voting in more than two dozen states.
