By Dan Williams
TEL AVIV (Reuters) - Islamic State's battleground setbacks in Syria have increased the chance of an attack by the insurgents or their allies on Israel and Jordan, Israel's military chief said on Monday.
While focused on shoring up its Syrian and Iraqi fiefdoms, Islamic State has in recent months stepped up attacks abroad and issued public threats to include Israel among its targets.
Lieutenant-General Gadi Eizenkot, chief of Israel's armed forces, said that with Russia intervening last year to help Syrian President Bashar al-Assad, the insurgents' advance had been largely arrested.
An exception to this, Eizenkot said, was in the southern Syrian border nexus with Israel and Jordan.
"The successes against ISIS raise the probability, in my eyes, that we will see them turning their guns both against us and against the Jordanians," he told a conference hosted by Tel Aviv University's Institute for International Security Studies.
Islamic State itself does not have a strong presence on Syria's south-west border region, but one of several Islamist forces in the area, the Yarmouk Martyrs' Brigade, is believed by its opponents to be linked to the ultra-hardline militant group.
It has fought rival insurgent forces from Syria's al Qaeda offshoot, the Nusra Front, and Ahrar al-Sham for control of territory next to the Israeli-occupied Golan Heights and close to northern Jordan.
"In their strategic logic, there is a certain logic in connecting Israel with Jordan," Eizenkot said, and in the border area "they are not experiencing what the organization and other global jihadi groups are experiencing inside Syria".
A voice recording release on social media three weeks ago and attributed to Islamic State leader Abu Bakr al-Baghdadi warned that Israel was a target.
Jordan, one of two Arab countries to have signed peace treaties with Israel, has largely weathered the upheaval in much of the Middle East over the past five years, though it has absorbed major refugee influxes from Syria and Iraq, another neighbor wrecked by Islamic State insurgents.
Jordan has low-key military backing from the United States and Israel, cooperation that the parties rarely discuss publicly.
Israel has formally kept out of the almost five-year-old Syrian civil war, though it has launched occasional bombing raids to thwart suspected transfers of advanced arms by Assad's government to allied Lebanese Hezbollah guerrillas.
Hezbollah, which fought Israel's technologically superior military to standstill in the 2006 Lebanon war, remained a major threat and stood to receive boosted support from its Iranian patron thanks to the lifting of international sanctions against Tehran, Eizenkot said.
But he also described Hezbollah as cautious to open a new front with Israel, noting that while the Shi'ite militia had gained combat experience reinforcing Syrian government forces against Sunni Islamist-led rebels, it had also suffered losses.
Some 1,300 Hezbollah guerrillas had been killed and almost another 5,000 wounded in Syria, out of a regular fighting force of 20,000 and a reservist force of 20,000-25,000, Eizenkot said.
Hezbollah generally does not publish details on its casualties, and says it is ready to fight Israel again.
(Editing by Dominic Evans)