It looks increasingly likely that the United States, in conjunction with key allies, has decided to launch a limited military strike in the coming days to punish Syria for its apparent use of chemical weapons on August 21.
But U.S. President Barack Obama has also made it clear that he seeks to fulfill that goal without destroying the regime of Syrian President Bashar Assad, killing more innocent people, or sparking further regional escalation of the war.
While the United States has considerable military assets at its disposal, including ships in the region carrying scores of Tomahawk Land Attack Missiles (the likely stand-off weapon of choice), it is a challenge to calibrate the response just right. Too little force could have little effect, while too much could backfire.
The United States is not alone in this delicate balancing act. Assad, too, must carefully weigh his options as he ponders how he can respond to an anticipated U.S. strike without unleashing the wrath of the U.S. military and, as a result, jeopardizing his own survival.
Predicting Assad's response requires, in part, an understanding of the reason for his use of chemical weapons in the first place. Was it a step taken out of frustration or desperation? If the regime believes it needs to maintain a chemical weapons option it might be more inclined to respond. Conversely, was it a misstep, possibly reflecting divisions within the regime or poor command and control? In that case, retaliation might be less likely.
Assad's response will depend, perhaps to an even greater degree, on the nature of U.S. action and how he perceives U.S. strategy and intentions. Is a strike seen as merely symbolic? Substantive but limited? Or is it part of a new effort to overthrow the regime? A panicky regime that feels its survival is at risk is more likely to miscalculate or escalate. So too, conversely, is an overconfident one that believes an attack is little more than a slap on the wrist indicating weak U.S. and international resolve.
To reduce the risk of escalation, Obama has publicly telegraphed his intentions to Assad, making it clear that the U.S. goal is not to topple the regime. A similar message has likely been passed on to Syria's key allies, Russia and Iran.
As careful as both sides might be to calibrate action and response, developments can always spin out of control. Assad knows the "law of unintended consequences" well from earlier in his presidency: in 2005 Hezbollah's suspected assassination of former Lebanese Prime Minister Rafiq Hariri ultimately resulted in Syrian troops being forced to leave that country. In 2007 Syrian efforts to develop a covert nuclear capacity ended when Israel bombed the suspected reactor site. In 2011 efforts to crush largely peaceful protests sparked the current bloody civil war. This month's use of chemical weapons is another action for which the consequences — an impending U.S. military attack — were almost certainly not those that Syrian officials intended.
Moreover, in the fog and friction of war intelligence is imperfect and bombs and missiles don't always end up in the right place. Given the deaths of hundreds of civilians when the United States bombed the Amiriyah shelter in Baghdad in 1991 as well as the accidental bombing of the Chinese Embassy in Belgrade in 1999, American targeteers had better be very sure they know what not to hit in Damascus this time around. If a U.S. attack results in high Syrian civilian casualties or costs the lives of key regime figures, Assad might find himself under greater pressure to respond.