In a move that would primarily benefit the world’s largest economies and most bloated governments, the Biden administration has proposed that all the world’s countries agree to impose corporate taxes at a rate no lower than 15%. Biden also proposes punishing countries that don’t adopt the minimum, by imposing heavier taxes on U.S. subsidiaries of companies headquartered in those countries. In describing the initiative, Treasury secretary Janet Yellen made her aim all too clear: “It is important to work with other countries to end the pressures of tax competition,” she said in a speech to...