The problem isn’t that they’re playing nice. As you said, that’s a good thing on the surface. The problem is A. Russia helping us form a Cyber Security Unit to guard against any cyber threat is like Bill Cosby teaching young men how not to be rapists (oh wait, that’s happening, too) and B. Playing nice is fine until Putin decides to see what he can get away with now that he’s bffl’s with the leader of the most powerful nation in the world. He may decide it’s totally ok to continue to repress all human rights in his country, to continue to support dictators like Assad, to continue to invade and try and annex other territories and countries, heck, let’s bring back the whole Soviet Union! And we’ll let him do whatever he wants simply b/c we don’t want to get in a fight? What’s next, we’ll lift sanctions on North Korea and let Kim Jong Un continue to be a ruthless dictator and take over South Korea simply b/c they have missiles? That’s not how foreign policy works. Yes, it’s a very, very delicate situation, most foreign policy is. We certainly don’t want to provoke a nuclear armed country, but there’s a balance we must find where we also don’t roll over and let them do whatever they want in their insatiable quest for power and suppression of all dissidence. Also, you’re not giving much credit to Putin by thinking he’d launch nukes at us because the US was mean to him. Most world leaders (except maybe Trump and Un) understand the gravity of a nuclear war. They understand that retaliation would happen and no one would win.