I'm not sure that ring against IS and jihadis alone forms much of a basis for optimism: there already is a war against them going on, one which Putin claimed to want to help with, it whose help has yet to materialise. I'm not aware, for example, that there is any Russian input whatever into the force being assembled to retake Raqqa.
Russia presents zero threat to the US: it is a long way away (Ok there's the Bering Strait) its armed forces are way inferior and I am not aware that there is any remote desire to nuke the yanks :-)
Russia is also a minor threat to Western Europe as long as we can count on the US as an ally. Of course Trump is dead right to complain that Europe should spend more on defence, but the worry is that he will take it further than that. In short, I could trust Trump given the chance, but no way would I trust his opposite number. We need to wake up to the idea that Russia could become serious threat to our security and way of life. I know 'liberal' is not flavour of the month around here but believe me it has a lot going for it.
Who wants to return to the Cold War? Why Russia of course. Two big empires carving the world up between them. That's why I hope wise counsels prevail in Eashington.