The end game is not nuclear war.

While we've never had a full-scale nuclear war, it's doubtful that the banksters and arms dealers who really run the world could make a lot of money off one, so they won't permit one on their watch (if they can help it--after all, stuff happens...). This stands true for the USA, China, and Russia banksters and arms dealers. A full-scale nuclear war would destroy the global economy (and the nuclear powers involved).

The end game is the economic downfall of the USA (something both China and Russia would love to see), and that's relatively easy to accomplish.

One strategic nuclear strike on a big port city on the west coast, and hundreds of billions of dollars would be vaporized in a flash, and hundreds upon hundreds of billions of dollars would be diverted to reconstruction and relief for years, maybe decades. That would eliminate the USA as a global power, leaving China and Russia to divide the globe up between each other.