The governments decades old diplomatic campaign against Taiwan, whose independence is protected by American armed forces, has escalated into dangerous territory. Diplomatic pressure, and economic threats, have forced every country on the planet, except the United States, to stop selling weapons to Taiwan. Now, the popular enthusiasm for this approach, cultivated by decades of nationalist propaganda inside China, is putting pressure on the government to make some real threats to the U.S., to halt American arms sales to Taiwan. If the U.S. continues refusing (usually) to be intimidated, this escalation of threats could lead to war. The government believes that...