What are our military options in Syria?

A punitive naval or air operation to encourage a coup against Assad. These measures would reinforce existing economic sanctions. The two most viable tactics would be a naval blockade, to prevent Syria from exporting oil or importing a number of goods, and a limited air campaign to deprive the regime of assets that it values (like palaces). The hope would be that Assad’s cronies could be persuaded to depose him and then forge a power-sharing deal with the opposition, as a precondition for ending sanctions and ending the associated punitive military campaign.

A broader Balkans-like campaign to help depose Assad. In this option, air strikes would also target the heavy weapons that the Syrian army is using to shell cities; this could be combined with the creation of a no-fly zone for Syrian military helicopters and other aircraft over much or even all of the country, which could require up to a couple hundred aircraft operating in various bases on land and at sea in the region. This approach could also involve arming the Syrian opposition—though that would likely increase, rather than decrease, violence in the short term.

Creation of a safe zone for Syrian civilians. Safe zones are easier to declare than to enforce—and the Syrian army would surely contest any effort to establish one or more. But they might be accomplished using airpower and some modest number of outside ground troops. They could be partly modeled on the protection we afforded Kurds in Iraq throughout the 1990s, even while Saddam was still in power.