You’ve pretty much got it.
There are two reasonable scenarios here.
1. Putin is wary of our continuing military interventions in the Arab world, and is responding with his own intervention to prevent the balance of power shifting top far in our favor.
2. Putin and Obama have secretly made their Molotov-Ribbentrop pact, dividing which countries the socialist US government will intervene in, and which countries the socialist Russian government will intervene in. Hence, the US refusal to take action on Syria and silence on Russian actions there.
From what I know of Putin, both scenarios are probably equally correct, since I think, no matter what agreements he has made with the Obamunnist, he would hedge his bets and act in whatever way furthers his interests, knowing there will be no consequence.
There will be no consequence is the key.
Putin knows it. Flexibility , The Russians have it now.