The menace is already real. The C.C.P. is increasingly exporting its model abroad. Huawei and ZTE seek to build the world’s networks; WeChat and TikTok play a growing role in online discourse; Chinese cryptocurrencies could one day threaten the dollar.

As the United States again grapples with a challenge to its principles and its power, it will have to relearn the lost art of ideological warfare. Only by challenging the basic legitimacy of the Chinese Communist Party can the United