Assad is an Animal. An animal we need to keep the other animals in line but an animal none the less.
Animals can only be taught by Pavlovian conditioning.
Assad by his nature was going to test Trump's limits.
When Obama declared Chemical weapons a "Red Line" Assad instinctively crossed it just to find out what his reaction would be. Obama's reaction was of course nothing.
Now, Assad knows what he can't get away with.
Putin is pissed and rightfully so. However, relations between Washington and Moscow were going to go no where so long as a substantial part of the American electorate was convinced that Trump was Moscow's bitch. As of today no one believes that. It's going to take a while but things can move forward from here.
If this is as far as things go then we are good. If Trump decides regime change in Syria is in order than God help us all.