I don't know why anyone would assume this is necessarily contrary to an alliance with Putin. If you truly believe that Putin has peetapes on Trump and hacked the DNC to put him into office, it doesn't make any sense for Trump to throw all of that away for an airstrike in Syria. Putin keeps face by having advanced warning so his soldiers aren't killed, Trump keeps face in light of comments on Obama's weakness and accusations of letting Russia steamroll everything, maybe they get to rattle sabers a bit in public, then in a bit of time they "cool down", sign some treaties, lessen sanctions, and everyone is happy. I don't think Russia cares much about Syria/Assad on a personal level, they just care about potential oil pipelines and maintaining a geopolitical presence in the Middle-East.