To be fair, the Fed distanced itself from Mr. Dudley’s suggestion. But he was merely stating what is painfully obvious. The Trump administration — and the Republican Party — threatens the institutions of economic policymaking in the United States. Historically, it’s been radical governments in Europe and Latin America that elicited a hard line from conservative central bankers. It’s extraordinary that this possibility is now being canvassed in what remains the heart of global capitalism.

The world economy needs leadership from Europe: No one has more to lose from a collapse of multilateralism. The eurozone is perched on the edge of a recession — a hard Brexit will make matters worse — but a sharp slowdown in Germany means that for once the interests of North and South are actually aligned. The eurozone needs investment. But it has its own deep political dysfunction to deal with.

Even today, when bond markets will pay the German government to borrow, it is not clear whether Chancellor Angela Merkel’s ailing coalition government can agree on an expansive fiscal program. It would need the Bundestag to declare an economic crisis to release it from the strictures of its austere fiscal policy.

The fact that the world has not yet tipped into recession must in large part be credited to China. This is not to impute superhuman powers or monolithic unity to Beijing. The Chinese government has its hands full managing a nasty combination of slowing growth and a dangerous credit boom. China’s shadow banking sector is a worry, as are the country’s growth-addicted regional governments. China’s corporations piled up cheap dollar debt and are now subject to the erratic upward trajectory of the dollar. And behind the scenes, there are persistent rumors of tension between President Xi Jinping’s clique and that of Premier Li Keqiang.

And yet, in handling both its internal and external problems, China, unlike the United States, at least appears to have a playbook. It is not only synchronizing fiscal and monetary policy but is also using banking regulation and foreign exchange controls to contain the risk of capital flight. Once criticized for resisting the upward pressure on the value of its currency, Beijing is now expected by Washington to pull every lever to stop the yuan from devaluing. And even setting aside the contradictory noises from the Trump administration, there are few in the West who would want to see China liberalize its balance of payments and risk the kind of capital flight that rocked global financial markets in 2015 and 2016.