BEIRUT — The Gaza war has pushed together powerful Iran-backed Shia Muslim paramilitaries with militant Sunni factions in what appears to be closer cooperation between groups that differ in religious ideology but are united by opposition to Israel and the United States.
Hamas, which launched the attacks on Israel two months ago that sparked the war, is a primarily Sunni Muslim Palestinian movement. The group — whose name is an Arabic acronym for the Islamic Resistance Movement — is an offshoot of the Muslim Brotherhood, the powerful Islamist movement that was founded in Egypt in the 1920s.
