IN Afghanistan’s Logar Province, just south of Kabul, the geopolitical future of Asia is becoming apparent: American troops are providing security for a Chinese state-owned company to exploit the Aynak copper reserves, which are worth tens of billions of dollars. While some of America’s NATO allies want to do as little as possible in the effort to stabilize Afghanistan, China has its eyes on some of world’s last untapped deposits of copper, iron, gold, uranium and precious gems, and is willing to take big risks in one of the most violent countries to secure them.

In Afghanistan, American and Chinese interests converge. By exploiting Afghanistan’s metal and mineral reserves, China can provide thousands of Afghans with jobs, thus generating tax revenues to help stabilize a tottering Kabul government. Just as America has a vision of a modestly stable Afghanistan that will no longer be a haven for extremists, China has a vision of Afghanistan as a secure conduit for roads and energy pipelines that will bring natural resources from the Indian Ocean and elsewhere. So if America defeats Al Qaeda and the irreconcilable elements of the Taliban, China’s geopolitical position will be enhanced.

This is not a paradox, since China need not be our future adversary. Indeed, combining forces with China in Afghanistan might even improve the relationship between Washington and Beijing. The problem is that while America is sacrificing its blood and treasure, the Chinese will reap the benefits. The whole direction of America’s military and diplomatic effort is toward an exit strategy, whereas the Chinese hope to stay and profit.

But what if America decides to leave, or to drastically reduce its footprint to a counterterrorism strategy focused mainly on the Afghanistan-Pakistan border? Then another scenario might play out. Kandahar and other areas will most likely fall to the Taliban, creating a truly lawless realm that wrecks China’s plans for an energy and commodities passageway through South Asia. It would also, of course, be a momentous moral victory achieved by radical Muslims who, having first defeated the Soviet Union in Afghanistan, will then have triumphed over another superpower.