Any Israeli attempt to reoccupy Gaza in its entirety would need an estimated force of 25,000 soldiers to strike into the main urban areas, military experts have told The National.
The city of Deir Al Balah, in the middle of the strip would probably be the first target, which would require considerable aircraft and artillery commitments, they said. If Prime Minister Benjamin Netanyahu authorises his reported “updated strategy” to reoccupy all of Gaza, the major deployment of ground forces, alongside heavy firepower, would inevitably result in high casualties on all sides, they warned.
The troops, in addition to the three divisions already present, would draw on Israel’s combat reserves, which are already depleted in its battles against Iran, Hezbollah, Syria and the Houthis.
Fighting in urban areas is extremely dangerous, and almost 50 Israeli soldiers have been killed in the last three months in Gaza. This has led to questions in Israel over the high fatality count in pursuit of the return of the estimated 20 living hostages.
Furthermore, Israel would have to call up a considerable number of reservists from a force that has been on operations for nearly two years.

Hostage operations
An operational priority would involve the use of multiple reconnaissance drones to map the new layout of urban areas that have become “moonscapes” following previous bombardments.
For Deir Al Balah, a battalion of combat engineers would be needed to flatten the broad avenues of approach to prevent vehicles coming under fire from any remaining high-rise buildings or strongpoints, while also removing IEDs and booby traps.
Special forces from the Samur squadron of “tunnel rats” would simultaneously filter into the area seeking to find and release the remaining hostages.
That operation would be done as speedily as possible because Hamas had made it clear if the Israelis go into the city the hostages will be killed immediately, said Dr Lynette Nusbacher, an expert on Israeli military doctrine. “The Israelis are going to try very hard to snatch them fairly briskly as a cordon is established,” she said.
Heavy brigades
That cordon would require at least five brigades to prevent any Hamas fighters from escaping as strongholds are pounded with firepower. The Israelis would then use “mobility corridors” to prevent Hamas from moving from city block to city block.
“Joint fires”, the name given to mixed artillery and air power salvos, would be further deployed to pummel any strongpoints in the knowledge that no civilians are present.
“To hold with boots on the ground, the Israelis are going to use maximal application of air power and artillery, they're going to absolutely pummel the place,” said Dr Nusbacher, a former British army intelligence officer.
Infantry moving in armoured vehicles would be cautiously deployed on the ground. The units would consist of armoured brigades in Merkava V tanks, including their advanced surveillance systems, as well as the D9 armoured bulldozer.
Central to the mission will be finding the underground networks via the hidden access shafts and avoiding Hamas’s well-honed guerrilla tactics, which have led to high casualties. To hold major urban areas of Gaza, the Israelis would also need to quickly build concrete strongpoints for the infantry to use as patrol bases.
Reserves dry
“The first thing, presumably, this operation will require is another substantial call-up of reservists,” said Richard Pater, director of the Anglo-Israeli Bicom think tank.
Israel can draw from a pool of 465,000 reservists to add to its deployed force of 170,000. But many of the part-time soldiers have been at war for months, which is a drain on families and the economy.
“The military is not so enthusiastic about this,” Mr Pater added. “After all, they have been only just been removing soldiers from the front in recent months.”
Dr Nusbacher said the operation would have to be phased even if the Israelis conduct a huge mobilisation. She added that the Israeli army chief was likely to be giving Mr Netanyahu’s war cabinet the difficulties over mobilisation numbers and his predicted casualty figures “that are making their blood run cold”.

Civilian own goal
Another major question in the operation, forced upon the military, will be how to remove the two million Gazan civilians from the combat zone. Central to not scoring another major humanitarian own goal will be channelling the non-combatant population to the south, using SMS messages to give directions.
“Where do you move the civilian population in the meantime?” asked Mr Pater. “That's the big question.”
Dr Nusbacher said it would be a “vast task where the population numbers are significant, and the humanitarian consequences daunting”. She added that the military would not “want to be operating in a humanitarian disaster area, which this would be”.

High casualties
Urban fighting will inevitably take a “horrific toll” on the military with deaths, injuries and psychological casualties. “Urban operations are very casualty-intensive, and if you go to Israel now you see young amputees, something not seen in a generation since the [1980s] war in Lebanon,” said Dr Nusbacher.
Another military source, linked to Israel, suggested Mr Netanyahu would still be supported by the hard-right members of his cabinet who want to take control of Gaza, even if it resulted in a slow operation with high casualties, “which looked like a quagmire”.