Due to the current crisis in Syria, with the Syrian military fighting rebels and the alleged gunning down of civilians by the Al-Assad regime, many are wondering if a US-NATO intervention is likely. It seems that now, with a recent UN draft resolution being bough to light, an intervention may very well occur.
Just two days ago, the American magazine Foreign Policy received a copy of a UN draft resolution which calls for the Al-Assad regime to comply with its demands in 15 days or "additional measures" will be adopted "in consultation with the League of Arab States." 
The resolution itself calls on the Syrian government to do such things as "allow full and unhindered access and movement" for all Arab and international media. However, this request is quite strange as just this past December, an Arab League mission was sent to Syria to investigate and found "nothing frightening." Yet it seems that this was not satisfying to the Arab League and they are pushing for another inquiry.
The resolution also demands that the Syrian government "cease all violence and protect its population" and "withdraw all Syrian military and security forces from cities and towns, and return them to their original home barracks." However, such an action could allow for the Syrian rebels to retake those towns and cities and to organize and regroup, thus forming a much more organized and cohesive resistance against the Syrian government than is seen currently. This is quite plausible as the rebels are being back by the West. According Philip Giraldi, a former CIA analyst, the Syrian rebels are being given weapons that are transported via "unmarked NATO airplanes," that "volunteers from the Libyan National Transitional Council" are being brought in to aid the rebels and that
French and British special forces trainers are on the ground, assisting the Syrian rebels while the CIA and U.S. Spec Ops are providing communications equipment and intelligence to assist the rebel cause, enabling the fighters to avoid concentrations of Syrian soldiers. 
It must be noted that the Arab League members are all US client states and that as such this resolution plays into the hands of the US and its European allies, who want to intervene in Syria. Turkey also plays a role in this, as not only are they a base of support for the Syrian rebels, but "Ankara's foreign minister, Ahmet Davitoglu, has openly admitted that his country is prepared to invade as soon as there is agreement among the Western allies to do so."  (emphasis added) The passing of this resolution could potentially allow for an agreement among the US-NATO alliance to be reached, thus allowing for a Turkish invasion of Syria.
An intervention into Syria is quite important in America's war plans for Iran. A top US aide recently stated that "The toppling of Syrian President Bashar Assad's regime would serve a serious blow to Iran and would serve to further isolate the Islamic Republic" and that the overthrow of the Syrian government was "inevitable."  The toppling of the Syrian government would mean that Iran would be surrounded by countries that are US allies or partners, thus making it much easier to carry out Washington's invasion as they would not have to concern themselves with the possibility of outside resistance coming into Iran.
It seems that intervention into Syria is only a matter of time.