For months, Syrian opposition forces fighting government troops have been calling - with very little success - for foreign military intervention.
But Western defense experts are debating whether the establishment of a no-fly zone over Syria might get more international support.
Analysts said it is essential to first define the parameters and goals of a no-fly zone - an airspace in which certain aircraft, especially military ones, are forbidden to fly.
Retired Navy Captain Ben Renda flew aircraft patrolling the no-fly zone over northern Iraq in the late 1990s, said "If the goal of the no-fly zone is to be another arm in the rebels' military game plan, that would not be received well."
However, he said "if the no-fly zone is implemented to provide safe havens for refugees, for example, then that would obviously probably garner more international support and be an easier sell both domestically and internationally."
U.N. support not needed
If an international coalition decides to impose and enforce a no-fly zone over Syria, it does not necessarily need the United Nations to approve the action to give it legitimacy.
Experts say there was no U.N. Security Council resolution establishing the no-fly zones over southern and northern Iraq from 1991 to 2003. Those zones were patrolled by the United States and Britain, with some initial help from France.
But last year the Security Council passed a resolution setting up a no-fly zone over Libya to protect civilians from attacks by the forces of Libyan leader Moammar Gadhafi. At the same time, the resolution authorized member states to "take all necessary measures" to ensure the ban on flights.
Russia and China abstained from voting on the resolution, in essence giving the go ahead for the Libyan no-fly zone. But Moscow and Beijing said the action ultimately led to regime change, an outcome the two countries did not sanction.
Paul Smyth, a British defense expert and a former Royal Air Force navigator in a squadron patrolling the no-fly zone in southern Iraq in the 1990s, said Russia and China are now more cautious.
"The difficulty with Syria compared to Libya, is that whereas Russia and China perhaps gave approval to a resolution for Libya, they found that it was not used in the way that they had hoped it would be used," Smyth said. "I wouldn't say that they had been duped, I wouldn't use that term, but having been bitten in Libya, they are unlikely to repeat the same mistake in Syria."
Russia and China have already vetoed three U.N. Security Council resolutions on Syria, some of them calling for economic sanctions on President Bashar al-Assad's government. Experts say it is highly unlikely Moscow and Beijing would sanction the establishment of a no-fly zone over Syria.
U.N. backing preferred
Sean O'Connor, a military expert who writes for the British publication Jane's, said it would be preferable to get U.N. approval for a Syrian operation.
"Could we do it without U.N. support? Yes, it's possible, we could actually do that," he said. "U.N. support is a political requirement, but not a technical requirement - let's put it that way."
Retired Navy Captain Ben Renda agreed.
"I would assume that the U.S. does not want to go at it alone, that we want a broader coalition," he said. "If this were to be the plan, you want a broad coalition with everyone contributing - obviously money and forces - to help this be a joint effort… Just as was the case with Libya, having our Arab partners step up to be part of the solution, I think, will be critical."
Analysts said it is unclear whether the international community has the political will to get involved in another conflict, especially at a time when many western countries - including the United States - are cutting their defense budgets.