“what happens in the U.S. affects policies elsewhere”
It does in some ways. The US has the world’s largest reserves of coal. If the EPA restricts the use of coal in US power plants, then this will drive the price of US coal even lower, making it more attractive in China and India. China and India will increase their imports of US coal to further reduce their costs of energy production. In effect the US citizens will be subsidizing the costs of energy production in China and India. The Chinese and Indians will be laughing all the way to the bank about the stupid Americans.