Considering there are most likely other NATO civilians on that plane... it wouldn't be hard to be backed by other countries to reply back with some sort of action. I guess first, they will need to prove that Russia was behind this and prove that the Russian government had some sort of backing in it. Most likely will just be a bunch of apologies... "so sorry we just accidently killed 300+ people, our bads. We won't shot down the wrong plane next time.."
that's pretty much what we did when we shot down a civilian airliner oke: