When protests over the Israel-Hamas war took root on Columbia University’s campus last spring, Mahmoud Khalil became a familiar, outspoken figure in a student movement that soon spread to other U.S.

Israel accused Hamas of rejecting a U.S. proposal to extend phase one of the ceasefire deal. Describing the aid stoppage as "blackmail," Hamas said it was ready to begin talks for the next phase.

Critics say Mahmoud Khalil was unlawfully targeted for his activism; the government essentially describes him as a terrorist ...