The US is now wading into ever murkier waters in Syria with unpredictable consequences. That the Syrian rebels have been better armed in recent months was obvious by their ability to take out government tanks and the hundreds of Syrian government soldiers killed. Saudi Arabia sees the regime of Bashar al-Assad as little more than a client of its great rival, Iran, and would like nothing better than to see it replaced by a Sunni Islamist government that would realign in the direction of the oil-rich, religiously conservative monarchy. Qatar, a fellow Sunni monarchy, shares a similar view toward a government dominated by Syria's Alawite majority, followers of a offshoot of Shiite Islam – a religion that the Gulf monarchs view with fear and contempt.
The US, too, would like Assad to go. Secretary of State Hillary Clinton has been unequivocal on this point, and US officials hope that if Assad falls, that will further isolate Iran in its showdown with the US and other Western powers over its nuclear program. But the US is far more squeamish about the sort of regime that might replace Assad than its friends in the Gulf, and that's where the road the US is following grows more perilous.
CIA officers are keeping weapons out of hands of "terrorist groups?" Perhaps. But an anti-tank weapon given to rebels via the Syrian Muslim Brotherhood is liable to end up anywhere once it crossed the border. Weapons are as fungible as cash in war zones, and typically flow to the best financed and effective. And some of the most effective rebel formations appear to be led by precisely the kinds of Islamists the US fears most.