A week truly is a lifetime in politics. Just a week ago–Tuesday, August 20–there was approximately zero chance that American airpower would be employed against the Assad regime in Syria. The following day, however, Assad’s henchmen employed chemical weapons to kill perhaps 1,000 people on the outskirts of Damascus. Now Secretary of State John Kerry is calling Assad’s actions a “moral obscenity” and vowing: “President Obama believes there must be accountability for those who would use the world’s most heinous weapons against the world’s most vulnerable people.”

Given such remarks by America’s top diplomat, it is little wonder that the conventional wisdom in Washington is that President Obama will soon authorize air strikes in Syria. The only question is what will be the scope and intent of American action. As I see it, there are essentially three options. Call them light, medium, and heavy.

The light option is to employ cruise missiles fired by U.S. and allied warships and aircraft a safe distance from Syria’s shores to blow up a few chemical weapons stockpiles and other regime targets to signal the world’s displeasure with the use of chemicals–a weapon that has carried special opprobrium ever since the dark days of World War I. This would entail a few days of air strikes whose import would be largely symbolic–to “send a message” to Assad without actually trying to topple him or to get rid of all of his chemical weapons stockpiles. This option might even extend to trying to kill Assad himself, but with little likelihood of success–witness failed decapitation strikes on Saddam Hussein in 2003 and (arguably) on Muammar Gaddafi in 1986.

The medium option would to go after the chemical weapons stockpiles in a more concerted manner, employing not just airpower but also Special Operations Forces if necessary. The object of this exercise would be not only to reinforce the norm against chemical weapons use but also to ensure that Assad’s chemical weapons are never used again–either in Syria or, heaven help us, outside of it. This would largely obviate the danger of chemical weapons slipping out of Syria amid the chaos that grips the country, but it would increase the degree of difficulty and danger to U.S. forces because such a campaign could not be conducted safely from long range. Even to support limited Special Operations incursions, the Pentagon would likely demand massive conventional forces be mobilized in the vicinity of Syria to safeguard the commandos.

The heavy option would involve months of air strikes to enable rebel forces to topple the Assad regime. The obvious model here is Libya 2011, but this would also carry echoes of Kosovo 2009. In both cases U.S. airstrikes were potent because they were employed in conjunction with ground action by rebel forces.

History suggests that air strikes in isolation are likely to be indecisive. Witness Bill Clinton’s cruise missile attacks on al-Qaeda in 1998 in Sudan and Afghanistan and his Desert Fox bombing campaign of Iraq the same year. President George W. Bush later aptly summed up Clinton’s mistake when he said: “I’m not gonna fire a $2 million cruise missile at a $10 empty tent and hit a camel in the butt.” Of course, from Obama’s perspective, Bush made an even worse mistake–getting the U.S. embroiled in two costly wars on the ground. No one is suggesting, however, the introduction of U.S. ground forces in Syria beyond perhaps some commandos and CIA officers. Obama will be making a mistake if he is so leery of any greater U.S. involvement in the Middle East that he opts for the light option–a few symbolic air strikes that accomplish nothing beyond displaying American pique. This will not enhance American credibility. It will instead send a message of irresolution that predators around the world will sniff out all too clearly.

From a strategic if not political standpoint, I believe the real debate should be between the medium and heavy options. As someone who has been arguing for a U.S. no-fly zone and air strikes in Syria for almost two years, it might be expected that I would automatically opt for the heavy options. The problem is that in the intervening time, U.S. inaction has allowed the jihadists to become the strongest element within the opposition. U.S. action to topple Assad now, before we have properly armed and trained more moderate rebel forces, risks throwing the country into perpetual chaos or allowing jihadists to seize control of significant territory.

The medium option, on the other hand, would allow us to vastly reduce the risk of chemical weapons proliferation without toppling Assad quite yet. The problem is that this would be an option very hard to carry out–it would involve significant intelligence challenges to identify the location of Assad’s chemical weapons and it would involve significant risks for the insertion and extraction of Special Operations Forces. Otherwise, if it relies on airpower alone, this option likely would be ineffective.

So in the end I still think a strategy aimed at regime change–employing American and allied airpower in conjunction with coordinated ground action by vetted and responsible elements of the Free Syrian Army–is the best American response. But I have a lot more qualms about this option now than I had in 2011 when the Syrian civil war was still young and the country had not yet become so polarized.