No plan, but a pattern.
1) topple a government that doesn't take orders from us or washington
2) farm out contracts for the "rebuilding" to your mates
3) oh well the rebuilding went tits up but at least your mates got paid
4) failed to put in a puppet government, but at least the old one's not around to be a threat. declare mission accomplished, exit through back door
They'll make pleasant sounding noises about fighting ISIS but it's not hard to see what they really mean when they ask who's going to rule syria after they win. They're assuming Assad won't be there any more, I wonder why they might do that?
Pretty arrogant imperial worldview - We get to decide what governments other countries can have, and they don't.