Like I said the other day, I expect that even if Congress declines to authorize the use of military force in Syria, President Obama will order a variety of covert actions in support of the rebels.
How can we know if these are occurring? Basically, I think we should look for things happening that the rebels would have liked to do a long time ago but were unable to carry out. For example, assassinations of senior Syrian officials. I could see, for example, stealthy drone attacks on the convoys of the officials who oversaw the use of chemical weapons -- but credit being given to Syrian rebels. I also think we could see things like signals intercepts being passed to the rebels, as well as other helpful intelligence, like real-time satellite imagery. Basically, any anomalous action bears a second look.
Fast transmission of targeting info could significantly boost the effectiveness of the opposition, I think. I've been told that, during the Iran-Iraq War, the U.S. provided Saddam Hussein's air force with good photo imagery of Iranian military targets, such as major supply depots and corps-level headquarters, and that the subsequent Iraqi airstrikes broke an Iranian offensive and so changed the balance of the war.
Yet even as I discuss this, I wonder: If the rebels win, how will they treat Armenians, Jews, Christians, and other minorities?