US military interventions abroad -- at an absolute minimum -- have got to represent some reasonable path to a better future. It is amazing how even this simple and obvious test is almost never met by our actions. Instead, I think many folks substitute some test more like "Is the situation really bad?--if so, rev up the troops." To this end, Assad is clearly a bad guy. Assad (or someone) using poison gas on civilians is a bad thing. Russia providing cover for these bad things is also a bad thing. But what is the alternative? Obama's support of rebels in Libya is just a fantastic example we should all remember -- the Libyan regime was bad but we supported its overthrow in favor of a situation now which is clearly worse. Iraq-style regime change is out of favor for good reasons, but at least regime change advocates had a clear explanation of how they wanted to get to a better future with military action -- they were going to take the whole place over with massive military force and stand on it for a couple of decades until, like Germany after 1945, it becomes a responsible citizen of the world. The costs are high and I don't think it is in our long-term interests to do so, but at least there was a logical story.
What is the story in Syria? We kill a couple hundred folks with cruise missiles to avenge a few dozen folks killed with poison gasses and, what? Do the citizens of Syria really need yet another foreign power lobbing explosives into their country? The only argument I hear is that Assad crossed a line and now we have to show him what for. But this sounds like an 18th century aristocrat vowing to defend his honor after an insult. It's sort of emotionally satisfying -- take that, asshole! -- but where does it get us except further mired in yet another foreign conflict we have not hope of making better? We look back and criticize the major powers in 1914 for getting involved in the constant squabbles in the Balkans but do the same thing in the Middle East, the 21st century's Balkans.