Since China declared a “war on pollution” in 2014, environmental protection has become a top political priority, evidenced by tough regulations, enforcement campaigns, and an emphasis in official rhetoric. Stronger environmental enforcement has had mixed effects on US-China Business Council (USCBC) members. In many cases, it has helped level the playing field for foreign companies that already had strong pollution controls, since domestic companies are increasingly held to the same environmental standards as foreign companies. At the same time, the speed of regulatory change and sudden intensity of enforcement has increased costs and uncertainty throughout the supply chain.