Hamas political leader Ismail Haniyeh has been killed in the Iranian capital Tehran, according to Iran’s Revolutionary Guards Corps and Hamas on Wednesday, a major escalation that deepens fears of an all-out war in the Middle East. Haniyeh is the second leader of an Iran-backed militant group reported to have been assassinated in recent days. His death represents a significant blow to Hamas, eliminating its most public figure who headed up the group’s political operations while living overseas. In a statement, Hamas accused Israel of targeting Haniyeh and his bodyguard in a “strike” on where he was staying in Tehran,...