No. Sam said it best...
No. Not a threat to the United States and not our business.
If we go into Syria, it will be a disaster. If they use gas on their own people, they would not think twice about doing it on our men.
1. "Not a threat to the United States" is not a legitimate argument for neglecting to prevent a serious human rights abuse when we have the capability to do so. There's a moral imperative, as a bystander who can prevent it, to do something about it.
This would be like if you look outside your window and you see some neonazi-looking guy down the street who's holding a gun and pointing it down at a group of your neighbors who are lying in the fetal position. Your loaded hunting rifle is kept in a case just next to this window; you could easily take him out and stop whatever this tragedy is before it gets any worse. But, you decide, "hey, not my problem if they're not bothering me, sucks for those guys who pissed him off" and go back to sit in front of the TV.
2. As said above, the US has an AirForce that is very good at things, and fighter jets are not susceptible to chemical weapons attacks.
3. Even if, for some reason, the US assists a Turkish/NATO invasion with ground assets, you can bet that every single one of those soldiers will have received a refresher course on chemical attack defense protocol: