T-800: "Skynet knows that the Russian counterattack will eliminate its enemies over here."
That very well could come true since they admit Russia has overhauled their nuke program and the USA has not even started.
But I dont think it will even take that. All they have to do is invade through our southern border. Hell, they already have.
All we have is a few B1 Bombers and the Boomers under the water in the ocean.