The US is expected to block military aid to an Israeli army unit. What is the Leahy law?

Israel expects its top ally, the United States, to announce as soon as Monday that it's blocking military aid to an Israeli army unit over gross human rights abuses in the Israeli-occupied West Bank before the war in Gaza began six months ago.

The move would mark the first time in the decades-long partnership between the two countries that a U.S. administration has invoked a landmark 27-year-old congressional act known as the Leahy law against an Israeli military unit.

It comes as...