The Boycott, Divestment, and Sanctions movement—BDS for short—attempts to persuade the world to break off all economic and diplomatic relations with the state of Israel. Americans who’ve heard of BDS may think of it as a crotchet of left-wing cranks, but it now has budding support in Congress.

The BDS movement accuses Israel of imposing “apartheid” on the Palestinians. It holds companies and nations complicit in oppression unless they remove all financial and diplomatic relations with the Jewish state. The movement is in many ways a throwback to the Arab League boycott of Israel, adopted by the Arabs in 1945 to prevent Jewish emigration to the British Mandate—that is, to prevent the creation of Israel. The league tried to blacklist not just Jewish firms but any international company that traded with Israel. Eventually it fell apart because Arab companies liked profits more than they hated Jews.