Many years ago folks worried about the day China and Russia became friends. That may be our next war and one we probably won't win.
Friends? Whenever they pat each other on the back, they need to check for a dagger. Russia has huge land areas, lots of natural resources, and a dwindling population. China needs the land and resources, has a growing population, and shares a big (disputed border) with them. Thats not a situation for long term friendship.