Britain’s political system is in crisis after Brexit. Shortly after voters decided that Britain should leave the European Union, David Cameron, the prime minister and Conservative Party leader, announced his resignation. This led to a short but vicious leadership contest, which left the ambiguous “Remain” supporter Theresa May as prime minister by default. The insecurity ...

Nicholas Mulder’s new book, “The Economic Weapon: The Rise of Sanctions as a Tool of Modern War,” remakes debates over European history between the two world wars. It rescues the League of Nations from the enormous condescension of posterity, arguing that the league was neither ridiculous nor doomed. However, it also demonstrates that the league’s ...