What should other nations do? My strong recommendation to Canada, Mexico, Japan, the United Kingdom, and the European Union is to join together to create a free trade zone that excludes the United States, imposing at least a 10 percent tariff on all imports from America.

They should also threaten to limit American banks’ access to their public stock markets, put limits on what their citizens can invest in American companies annually, and increase taxes and regulations on American digital platforms.

They will be tempted to negotiate and do so individually. They should not. They need to negotiate from a position of strength. A non-U.S. free trade union will give them that strength.