In the southern Golan Heights, the Israeli, Syrian and Jordanian borders all meet. Just a few kilometers away, branches of the Middle East’s two most notorious terror groups have been fighting it out. The lack of fallout in Israel underscores the country’s surprising achievement – for five years it has stayed on the margins of Syria’s bloody civil war.

Vestiges of Syrian President Bashar Assad’s hold on the Syrian Golan disappeared two years ago. The Syrian army maintains a marginal presence a distance from the border at Quneitra, and the Druze village of Khadr to the north is controlled by local militias that communicate with the regime.

But Assad’s commando units have left their last positions on the Syrian part of Mount Hermon. Hardly anything is left of Syria’s massive fortifications to keep Israel from advancing on Damascus in the next war, as Israeli forces did when they turned the tables in the 1973 Yom Kippur War. Whatever weapons were left behind have long been looted by local rebel militias, which, without regime foes to fight against, are now making war on each other.

In the southern corner of the Golan sits a local rebel group, the Yarmouk Martyrs Brigade, which at the end of 2014 swore allegiance to the Islamic State. Some 40,000 people, among them more than 600 fighters, live in the villages and towns on the ridge opposite the Israeli border, between the deep wadis of the Ruqqad and Yarmouk valleys.

To the north and east a complex network of other local Sunni militias is in charge. Some of them are considered by Israel and the West moderate, such as the Free Syrian Army.

But their battle against the Yarmouk Martyrs Brigade is being led by members of the Nusra Front, the Syrian branch of Al-Qaida. In recent battles, the Martyrs Brigade took a few villages to the west until the Nusra Front took them back. A few hundred fighters did battle on each side.

During a recent visit by students of the U.S. Army War College to the Israeli side of the Golan, the American officers were surprised when their Israeli counterpart said that in the conflict across the border, “the ones that brought down the Twin Towers on 9/11 aren’t the worst we know of in the area.”

A shock for young officers

The policy Defense Minister Moshe Ya’alon outlined to Haaretz a year and a half ago is still in force: Israel is providing the more moderate local militias and the inhabitants of the villages under their control with food, clothing and medicine. It has also given medical care to around 2,100 of them in Israeli hospitals.

The Nusra Front keeps its distance from the border. Meanwhile, frequent reports in Assad-friendly media outlets of an alliance between Israel and the Nusra Front – that is, Al-Qaida – are vehemently denied in Jerusalem.

The name of the Israeli officer in charge of this stretch of the border is classified; I’ll call him Col. G. He told Haaretz at the border a few days ago that the recent exchanges of fire between the militias in the southern Syrian Golan can clearly be heard from Israeli positions.

The battles have a loose connection to events in the main arena. The Golan Heights, a past focus of both Hafez and Bashar Assad out of fear of Israel, is now all but marginal.

Meanwhile, from an Israeli perspective, although the terror attacks in the Golan in recent years have been carried out by groups close to the regime (Hezbollah and Druze and Palestinian squads fielded by the Iranian Revolutionary Guards), the main concern is the Yarmouk Martyrs Brigade.

The Nusra Front took out the brigade’s previous commander and the new Saudi leader is enforcing a harsher religious line. As in the areas under Islamic State control, the brigade is enforcing modesty rules on women and punishing men for alleged infractions of Muslim religious laws.

The Israelis are aware of the brigade’s awakening, along with threats by the Islamic State to attack Israel from the Syrian border. According to G., young officers in the Israel Defense Forces newly posted to the Golan “are a little in shock at first. This is a major challenge because the situation is very dangerous.”

When an armed man approaches the border fence at night, it’s quite likely to be linked to internecine fighting , G. says. “They don’t go around with signs telling us what organization they belong to,” he adds. “We could easily get dragged into unnecessary fighting if we don’t use good judgment and count to 10, but of course if a commander sees danger, we expect him to act.”

Work is underway to upgrade the Golan border fence and improve intelligence and preparedness. G. is girding for a broader attack that’s “not just three guys cutting the fence.”

Such a foray could occur for local reasons or the regional considerations of the Islamic State, which might need a resounding achievement against Israel if pressured by a U.S.-led coalition in Syria and Iraq.

“There’s the understanding that in Syria anything can happen. We don’t dictate events in the civil war,” G. said. “We have to understand that our influence is limited on what’s happening there and be modest about our ability to analyze and especially predict what could happen between the Syrians and themselves.”