“Apparently the previous administration believed “the proxy with the most promise” is ISIS.”
I think the previous administration was looking for a very different sort of promise. What exactly that was, I can’t guess, not having been in on O’s summits with Beelzebub.
Backed wrong proxies. Used drones willy nilly, as you allude. Drew red lines in disappearing ink. WTF WAS his Syrian policy? Something like the South Park credit resolution policy? Feed laxative to a chicken and see where on the game board it poops, and use that to decide?
The answer to 'why that policy' is found in Gladio.