For China’s leaders, the chaotic scenes unfolding in Afghanistan have served as a stinging vindication of their hostility to the U.S. might. “The last dusk of empire,” China’s official news agency said. The Chinese foreign ministry called it a lesson in “reckless military adventures.”

Any smugness in Beijing could be premature. China is now left scrambling to judge how the U.S. defeat could reshape the contest between the world’s two great powers. While the Taliban’s rout has weakened American prestige and its influence on China’s western frontier, it could also create new geopolitical dangers and security risks.