Barack Obama, the US president, has said it is a matter of time before Bashar al-Assad, the Syrian president, steps down, declaring: "Ultimately this dictator will fall, as others in the past have fallen."

"If the US, the international community, if responsible countries don't do anything fast then extremists do thrive on despair and the activists on the ground are getting more and more desperate … then al-Qaeda might just step in. We don't want external extremists hijacking our revolution."

- Karam Nachar, a Syrian activist

The UN estimates that more than 7,500 Syrians have been killed in fighting since the first protests began a year ago. The Syrian government for its part says that at least 2,000 members of the security forces have died.

But while Obama has repeatedly warned against unilateral US military intervention in Syria, John McCain, a Republican senator and Obama's rival for the US presidency in 2008, has been leading calls for US action.

McCain told Al Jazeera that he wants an international effort involving NATO and the Arab League to protect Syrian cities and towns, citing the examples of the wars in Bosnia and Kosovo.

He also wants airstrikes against al-Assad's tanks and artillery and to provide arms and offer sanctuary to the rebels.

"The Libya campaign is barely over, the [US] administration has just withdrawn from Iraq, they are trying to get out of Afghanistan, they are trying to avoid going into Iran, so the last thing they need is another war in another Muslim country."

- Jonathan Tepperman, from Foreign Affairs magazine

Alluding to a broader aim, McCain said that such action would be a blow to Iran and warned that it would be a strategic and moral defeat for the US if al-Assad clings to power.

Meanwhile, an NBC/Wall Street Journal poll on US public opinion in early March showed that 13 per cent favoured US military action, 11 per cent supported the supply of weapons to anti-government forces and 48 per cent wanted humanitarian aid for injured and displaced civilians.

So, should the US lead an intervention in Syria?

Joining Inside Story Americas with Shihab Rattansi to discuss this are: Jonathan Tepperman from Foreign Affairs magazine; Steve Clemons, the Washington editor-at-large for The Atlantic magazine; and Karam Nachar, a Syrian activist who says he is in close contact with Syrian rebels.

"The equation of a robust American ownership, a kind of 'nanny state' adoption of Syria, the region and all of its problems are exactly what the US has been trying to extract itself from, both because of cost and because the return from these things hasn't exactly been clear to the American people."

Steve Clemons, from The Atlantic magazine

How they are divided:

  • Barack Obama - the US president says he does not support military action in Syria, and that it is never the only option
  • Mitt Romney - the frontrunner in the Republican Party's presidential nomination race says Obama should have called on al-Assad to step down sooner
  • Newt Gingrich - the former congressman says he supports covert action
  • Rick Santorum - the former senator says he would consider military strikes in Syria
  • Ron Paul - the congressman says the US should stay out of Syria's conflict
  • Hillary Clinton - the US secretary of state wants a UN resolution condemning al-Assad

Source: Al Jazeera