Iran’s dumbest weapon is now holding the global economy hostage

Sea mines are “simple, uncool weapons,” Scott Savitz, a naval marine warfare expert at RAND who was stationed in Bahrain in 2001, told Fortune. They predate World War I and haven’t advanced much since; they look like the spiky metal balls you’d imagine from the movies, small enough to slip neatly into a fishing boat and packed with TNT and ammonium nitrate. 

But when they go off, they can snap ships straight in half, Savitz said. They have a “much greater effect, typically, than a missile,”...