The proposal, which has been drawn up by the military and presented to Binyamin Netanyahu, the prime minister, is intended to secure the 47-mile border against a growing Islamist threat if President Bashar al-Assad’s embattled regime loses control of the area.

The buffer would be modelled on the Lebanese security zone, in which the Israeli defence forces patrolled jointly with the South Lebanon army, a militia, up to 16 miles inside Lebanon from 1985 to 2000.

“We’ve presented the prime minister with a comprehensive plan to defend Israel’s border after, or perhaps before, the fall of Assad’s regime,” said a source close to the military planners.

“A buffer zone set up with the co-operation of local villagers lies at the heart of the plan. If the country remains unstable we might have to stay there for years.”

In recent months jihadist groups such as the Nusra Front, which Washington regards as a terrorist organisation linked to al-Qaeda, are reported to have infiltrated several border villages. Two of the villages, Breika and Bir Ajam, are less than a mile from the Israeli border.

Netanyahu, who visited Israeli outposts overlooking the rebel villages last month, watched construction workers erect a 20ft steel wall along the border to replace a rickety fence.

“The old fence was fine for more than 40 years,” said the military source. “We knew then that there was a strongman in Damascus. But not any more. The new wall will be good when it’s ready but without the buffer zone mortar and rocket attacks on Israel would be a daily event.”