The Grapevine is a long mountain pass, the gateway from North to South. Accordingly, it would make an excellent chokepoint in case of Chinese invasion. But the US military is overcommitted & unprepared. Who, then, will hold the pass?

The Turks, of course, back to defend their long-lost territories.

(They have Janissaries, and great big bombards. It's their civilization's unique trait!)