My theory of imperialism is this: if the people of the region want it, the US won’t support it (unless there is something potentially to make it worthwhile, like oil in Libya, but they’ll still try to fuck shit up afterwards). That’s the yardstick you should measure ‘imperialism’ by, instead of abstractions on what you think it wants. People in Syria wanted an intervention against Assad, they didn’t get it. Voila. If they didn’t want intervention, they probably would’ve got it. People in Iraq did not want an invasion, they got it, voila. That’s how it works.
The US *did not want to take down Assad in Syria*, ever. It wanted to rid Syria of chemical weapons because it was clear that the regime might not be able to safeguard them, and because having them flying around is a regional threat (especially to one certain country). They threatened Assad, Israel came up with a deal and voila.
In my opinion, the fact that intervention in the case of Syria would clearly have been anti-genocidal and aligned with the will of the majority there meant that I (and loads of Syrians I’ve seen interviewed at the time) never believed it would happen. The fact that prolonging the conflict (which entailed keeping Assad in power) would be genocidal meant that it was going to happen.
Now, with the West bombing every single one of Assad’s enemies, perhaps those conspiratorial Arabs who were always suspicious of the Americans’ motives whilst others were getting their pants in a twist about how the US had it in for Assad (instead of for the Syrian people) were right.