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 closest 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.

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The three rebel groups that just joined ISIS could make that situation even worse. Two of the groups are small in number, but the Yarmouk Martyrs Brigade has hundreds of fighters. The Yarmouk Brigades has been at odds with al-Nusra Front and switched now to join what leaders of all thrwee groups believe is the future of Islam.

“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.”

“More recent reports indicated a closer alliance with [the Islamic State] due to tensions with JN [al-Nusra Front],” said Jasmine Opperman, a researcher at Terrorism Research & Analysis Consortium (TRAC). She said al-Nusra attacked the headquarters of the Yarmouk Brigade in southern Syria in early December 2014 following clashes between the two groups.

Al-Yarmuk Martyrs Brigade controlled an area near the Jordan-Israel border in March 2013. That same month, the brigade took as hostages some of the United Nations peacekeeping mission soldiers. Even so, Israel reportedly allowed the brigade to have its wounded fighters treated in Israeli hospitals.

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ISIS has been known for launching surprise attacks and opening new battlefronts when it seems to be losing. ISIS also has been criticized by many Arabs and Muslims for not taking its fight to Israel and instead fighting fellow Arabs and Muslims. An attack aimed at Israel may boost ISIS’s popularity in the Arab world and refresh its recruitment and funding efforts.

On the other hand, some of ISIS’s top military commanders were former officers in Saddam Hussein’s army, and they may resort to what Saddam did in the 1991 Gulf War when he attacked Israel with mid-range rockets, hoping to drag the Israelis into a conflict that he was losing.

An Israeli retaliation in 1991 could have jeopardized the U.S-led coalition that then included Arab countries like Egypt, Syria and Saudi Arabia. The same is true now.

WHY THIS MATTERS



Despite some recent tensions between the countries, Israel remains America’s closest ally in the Middle East. Attacks on Israel by ISIS or affiliated groups could further escalate war in the region, or they could further strain ties between the Obama administration and the Israeli government.

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“It would be more likely a sign of desperation, as were Saddam's attempts to lure Israel into the 1991 war as a way of breaking the Arab coalition against him,” said NYU’s Levin. At that time, continuous pressure from the first Bush administration and the installation of the Patriot anti-rocket system convinced the Israelis to refrain from reacting to Saddam’s attack.

Israel could launch a preemptive attack to destroy or significantly damage these ISIS-affiliated units whether by air or by ground forces. Israel used its advanced air force to launch attacks in Syria several times since the beginning of Syrian civil war in 2011.

Meanwhile, Israel has recently boosted its defenses in the Golan Heights, saying its main concern was to prevent any major weapon transfer from Syria to Hezbollah, the Lebanese guerrilla organization that has engaged in several rounds of war with the Israelis since the 1980s.

This article was updated at 3 p.m. on Tuesday, Dec. 23.

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