imho that was just posturing. If he has any intention of starting WW3, you wouldn't show your hand by making such a public announcement.
Even Putin isn't crazy enough to start WW3...right?
no he is not, he is trying to tell his citizens to prepare for the worst, if he wanted war, he should have started it when turkey(NATO ally) shot a russian plane.... if that happened to an american plane lets say shot in vietnam...it will be iraq all over again..