Due to proximity and natural resources in its borders, I honestly expect Afghanistan to fall into the Chinese sphere of influence after we leave.
What proximity?
Afghanistan and China share a (minuscule) border.
There are no roads that cross said border, though. All routes from Afghanistan to China go through Tajikistan (or other countries). And Kashgar is not exactly the most Chinese city in China.
True.
Actually getting to Afghanistan is almost certainly easier from Russia and India than from China. Oh, and from Iran, of course.
