The war against ISIS is taking a dangerous, perhaps inevitable turn. The terror organization has been keen to expand to southern Syria and the Syrian capital of Damascus. Now it says it has recruited three Syrian rebel groups operating in the south of the country in an area bordering the Israeli occupied Golan Heights — that have switched their loyalties to ISIS. This switch means that Israel, the U.S.’s closes ally in the Middle East, could be threatened from the southwest by the Egyptian ISIS group of Ansar Bait al-Maqdis in Sinai and by ISIS in southern Syria. The ISIS war is not going well at all for the US-led alliance in Syria. ISIS and al-Nusra Front, al-Qaeda’s branch in Syria, are still the dominant rebel groups in the country. The U.S.-backed Free Syrian Army is still not a reliable fighting force. “If Israel was attacked by ISIS, America would expect a proportionate response by Israel, which is militarily capable of defending itself,” said Geoffrey Levin, a professor at New York University. “America would counsel against sustained Israeli involvement because it could threaten the tacit alliance between America, Iran, Turkey, and several Arab states against ISIS.” The three rebel groups that just joined ISIS have been at odds with al-Nusra Front and have switched their allegiance to what it believes is the future of Islam. Two of the groups are small in number, but Al-Yarmuk Martyrs Brigade has hundreds of fighters.