An American weapon first dropped by stealth bombers over Kosovo in 1999 and then during combat in the post-9/11 wars will soon be used by Ukrainian pilots flying Russian-made jets to kill Russian soldiers. The weapon, called the Joint Direct Attack Munition, consists of a kit that turns a cheap unguided bomb into a highly accurate, GPS-guided weapon. It is usually referred to as JDAM (pronounced JAY-dam). The Biden administration announced this week that the weapons would be part of a new $1.85 billion military aid package, giving Kyiv a precision-guided bombing capability it has never had. When dropped from...