On October 7, 2023, the Palestinian Sunni Islamist group Hamas (a U.S.-designated foreign terrorist organization, or FTO) led surprise attacks against Israel from the Gaza Strip by land, sea, and air. More than 1,200 Israelis and foreign nationals (including at least 35 U.S. citizens in Israel) were killed on October 7, and Hamas and other groups also seized some 255 hostages. Iran has provided material support to Hamas for decades ands various Iran-backed groups in the region have targeted Israel, U.S. forces, and commercial shipping while expressing solidarity with Hamas. This book address various conflicts ensuing between Israel (with some help from the United States, other Western partners, and some Arab states) and Iran and its allies in Lebanon, Yemen, Syria, and Iraq.