We can't "let Syria cross a line without consequences", but we don't want to do regime change or take out Assad, but we do want to maintain our 'credibility', but we can't get the U.N. to take action with the Russians vetoing everything, but we can put together an alliance, but we don't really know what we want to replace the current mess, but we can't let it go on, and what about Iran...
(Subtext: what kind of superpower are we if we can't impose our will on other countries? Also, oil. Also Israel. Also FREEEEEEDDDDUMMMMMBBBB! Also, Iran, Al Qaida, etc. etc.)
You know what all the Very Serious People who've decided We Must Do Something need? They need something like an Intercontinental Mega-Taser, something that can be used on an entire country to 'force compliance' while still being able to pretend it's somehow humane and has no side effects.
That, or a freakin' Magic Wand.
There are no easy answers. There are plenty of bad ones - and it's indicative how many are coming from people who screwed the pooch the last time around. That makes them experts I guess. We'll be making process when we finally learn enough to stop listening to them.
(And how come there wasn't this much angst over Ruwanda at the time? What makes Syria so critical compared to all the other conflicts we've systematically averted our gaze from over the years? When we weren't aiding and abetting them, that is.)
Poison gas? Criminal despots? Real great track record we've got there. And it wasn't that long ago that we subcontracted torture to Assad because he was our good buddy in the War on Terror.
Whatever the Hell we end up doing in Syria, a good first step would be to admit we have no high moral ground here, and no credibility.