As Israeli military reservists were called up and Gazans prepared for the assault, there were fears that any incursion on the ground could turn months of sporadic fighting into a set-piece battle.

Unlike the West Bank, where the Israeli Defense Forces have concentrated their operations against suspected militants for six months, the Gaza Strip has been left largely intact.

The reason is obvious to both sides. Gaza is one of the most densely populated places on earth and most of the population of more than one million is made up of Palestinian refugees living in crowded shanty towns.

The leadership of Hamas, the Islamic Resistance Movement responsible for most of the recent suicide bomb attacks in Israel, is concentrated in Gaza City and the Jabalia refugee camp, where they are protected by thousands of fighters.

Unlike the West Bank, where Israeli forces earlier this year quickly overcame Palestinian resistance in “Operation Defensive Shield”, Gaza would be almost impossible to take and hold without using thousands of troops and risking many lives.

Israel’s control of the skies and use of tanks and armored personnel carriers would be of limited use in Gaza, where Palestinian fighters can hide and escape in back alleys and underground bunkers. They also have more sophisticated weaponry and home-made mortars to hit Jewish settlements, and anti-tank mines to destroy Israel’s main battle tanks.

Last month Israel cancelled an attack on Gaza over fears it had lost the element of surprise. The same fears will now be echoed and the army may have to confine its operations to air strikes and limited ground assaults, which would restrict the effect on the militant strongholds.