I don't have a crystal ball. The chinese don't have the capacity to "occupy" Afghanistan. They have the capacity and the will to economically influence afghanistan. If there is something to be extracted out of afghanistan, they will establish a footprint, pay $$$$ for protection, and reap the benefits of cheap local labor. Much like they've done in Southern Iraq. But remember, we invaded Iraq for the oil...or was it to secure the oil fields for the chinese..
The russians will not set foot in Afghanistan again in any large numbers.