It's very clear from the General Hao Ping article a couple of decades ago that they were planning on using chemical weapons to depopulate America. As I've long said, even with their nuclear preemptive strike on military targets, they don't want to hit cities per se. They want to blackmail the West into submission so that they can take the land, have the economy, have the granaries and the other things which the U.S. provides without destroying the infrastructure.