"Here's my cynical take on it. Putin ordered his patsy Trump to attack the Syrian bases, build up a fake enmity. Let things heat up between Russia and USA then further down the line broker a 'peace' deal which involves lifting sanctions on Russia. Everyone's a winner! Trump gets 19% of Rosneft, Russia gets sanctions lifted, and ExxonMobil get their deal. Politically, Trump can't lift sanctions, so this fake raising of tension is a good way of getting there eventually down the line."
While I don't think Trump is a puppet to Putin, I could see Putin running a gamble like that. Not a bad theory in my opinion either way.