Here's President Obama's national security advisor, Susan Rice, explaining why a strike on Syria is both necessary and useless:
Leaving Assad's regime unpunished and undeterred puts "Americans at risk of chemical attacks, targeted at our soldiers and diplomats in the region and potentially our citizens at home," Rice said in a speech in Washington as the Obama administration ramped up its efforts to build popular support for limited strikes in Syria….
OK, so shooting some missiles or whathaveyou is totally important. But Rice also guarantees that the strikes will change absolutely nothing.
Strikes would take aim at Assad's chemical weapons stockpiles and potentially "shake his confidence in the viability of his relentless pursuit of a military solution," Rice said. But they would not "aim to topple Assad or on their own to effect regime change" because, "as President Obama has made clear, it is neither wise nor necessary to do so."
Given this sort of argument, the question isn't why the vast majority – we're talking 60 percent to 80 percent, depending on the scenario – of Americans are against a Syria strike. It's why anyone is in favor of one.