it's a yin and yang thing. sure the world could be a lot safer place if after ww2 the soviets and the americans had excellent relations. we wouldn't have half the crap that's going on now. but it's simply that we were too different and would never get along. our views were way too different about everything. we'd never solve world wide problems in the same manner.
which brings us to today. the soviets were never trust, and can't be trusted to this day. even if putin puts on his thousand dollar custom suits and speaks of peace and all of that other crap, don't forget he's the former head of the KGB. they're just as untrustworthy as the day the cold war began.