As for McCain, I have to kind of agree with him. Obama has demonstrated a bad habit of drawing lines in the sand when we really can't enforce them. We drew a line with Assad and did what exactly?
We insisted on him giving up his chemical weapons and he gave up his chemical weapons.
Diplomacy isn't dog obedience training. You don't smack them on the nose until they accept that you are the alpha.
Correction: He stated that he would give up his chemical weapons and then chemical weapons were used two months later. And now, nearly a year later, they're mostly disposed of. I'll agree that it was a partial victory, but it's also an agreement that makes tactical sense for Assad. He has the upper hand in conventional forces. If chemical weapons fell into rebel hands, it could swing the strategic calculus against him. This removes a potential threat to Syrian state forces and earns him brownie points at the same time.
And no, it isn't dog obedience training. But it is somewhat like dealing with children. If you make lots of threats and then never carry through with them even when the rules are breached, eventually not only is that child going to ignore your threats, but so are the other children watching.
I know that sounds incredibly paternalistic and condescending, but the gist is the same. And no, the answer is not to beat your children constantly, it's to reserve your ultimatums for the cases where they're truly needed and where you are prepared to enforce the ultimatum. It's the old adage, "Don't let your mouth write a check your body can't cash."
The White House and the State Department have been writing checks that I just don't think Americans are willing to cash. Public support for any kind of military intervention in Ukraine is very low.