First, if it works against Russia, it can work against China. It's just harder. Level of dependence between many EU countries and Russian energy sources are com

First, if it works against Russia, it can work against China. It's just harder. Level of dependence between many EU countries and Russian energy sources are comparable to US trade with China. Second, there's a false assumption in your real-world example that China doesn't want to protect their environment. If the danger is real and serious, they will. Currently they are just playing catch up with economic activity and living standards and at some point the environmental issues will become to focus. There is already raising environmental awareness in Chinese cities due to pollution.