The problem, the aide says, is that rather than following through on promises to train and arm the FSA, in recent weeks, support for such moves seems to have waned in Washington.“We’ve made promises that are largely unfulfilled,” says the aide, “And it doesn’t take long for people to lose confidence.”

A month ago, the conventional wisdom in Washington was that the Obama Administration was about to finally get behind the Syrian rebels in a big way. “There was a bit of a consensus building that some type of [Defense Department] train and equip was worth doing,” the congressional aide said. “As of yet it’s totally unclear if that will happen…

“It looked like we were getting so close, not only to U.S. strikes, but U.S. increased support in terms of arms and aid,” says Dan Layman, media director for the Syrian Support Group, which represents Syrian opposition interests in Washington. “There is a concern that that aid is going to drop off.”

The rebels aren’t the only ones upset by the potential hold up. Gulf allies who’ve been pushing the U.S. to get more involved are also angry. “The Gulf feels misled,” Mustafa Alani, a Geneva-based security analyst with the Gulf Research Center, referring to the U.S. shift, told The Washington Post. “Certainly, there’s a fear that this means Iran will be much stronger. Strategically speaking, the Iranian position is going to be enhanced in the region.”