Uncertainties infused into the global economy by the trade war between the world’s two largest national economies probably have helped to produce a global slowdown and fears, perhaps somewhat self-fulfilling, of an approaching recession. The fourth-largest economy, that of heavily export-dependent Germany, is already shrinking. There, as The Economist reports, “interest rates are negative all the way from overnight deposits to 30-year bonds. Investors who buy and hold bonds to maturity will make a guaranteed cash loss.”…

From May 1937 to June 1938, there occurred the “recession within [the] Depression,” America’s third-worst 20th-century contraction. About the causes of this, as about so many economic events, intelligent and informed people disagree. However, one theory is that capital went “on strike.” Rattled and exasperated by the New Dealers’ regulatory fidgets, investors flinched from economic activity. If so, this episode contains a warning for protectionists who seem oblivious.

They fiddle with global supply chains, as though the world economy is a Tinkertoy that they can pull apart and reassemble with impunity. Actually, it is analogous to an Alexander Calder mobile: jiggle something here, things wiggle way over there, and there, and there. So: Tariffs on Apple (headquarters: Cupertino, Calif.) iPhones that are made (actually, just assembled) in China might help Samsung (headquarters: near Seoul, South Korea) Galaxy phones sell in America. This is “America First” in practice.