These would pinpoint firing bunkers and positions for Hamas rocket batteries and artillery, command posts and logistic hubs — but only as far as they can be seen. Much lies underground in the dozens of miles of reinforced ammunition bunkers and assembly workshops of rocket and missile parts, smuggled from Lebanon, Iraq and Iran.
Penetrating the web of tunnels and subterranean barracks clustered round Beit Hanoun in the north, Gaza City, and Khan Younis in the south, will be the first objectives of the ground operation.
Given the depth of some of the chambers and their heavy concrete protection, it will be a journey into the unknown. Hamas fighters are likely to be positioned as suicide squads, and some will be holding prisoners and hostages.
This makes the use of indiscriminate weaponry such as flame throwers all but impossible.
Still more daunting is the use of thermobaric weapons, bombs and grenades that suck out oxygen and ignite enclosed spaces with a deadly air-fuel mix.
Hamas is likely to have such weapons, too, as they have been used frequently in the Balkans and in Ukraine, their technology available on the internet.
Modern technology, surveillance and attack drones, electronic jammers, and laser-guided sniper weapons may have changed the face of this form of battle superficially.
An Israeli airstrike in Gaza. Ruined buildings will provide Hamas with effective defences (Photo: Getty Images)
Much of urban warfare has been constant since the siege of Troy, and the desperate scrambles up the ramparts of Spanish fortress towns by Wellington’s shock troops, like the “Forlorn Hope’”of Sharp and his comrades in the Peninsular War (1808-1814).
The key is the human factor of command and control, discipline, and allowing the forward unit commanders to take the initiative. It is for them to decide when to manoeuvre, feint, and engage the enemy.
Too much information, too much command and control from distant headquarters, can cause chaos. British troops patrolling Belfast and the Bogside in Derry in Northern Ireland in the early 1970s had to learn to reduce radio traffic between platoons working down parallel streets for fear of “blue on blue” friendly fire incidents.
British and French troops still train intensively for fighting in built-up areas, known as FIBUA. The British Army worked through mock villages on Salisbury Plain and at Deal in Kent. Now they share a state-of-the-art urban warfare centre at the home of the French paras outside Paris.
The hard lessons of wars past are never far away. The French have the reminder of the brutal experience of fighting in Algeria, brilliantly portrayed in Gillo Pontecorvo’s The Battle of Algiers (1966).
An Israeli soldier hugging a woman (Photo: Getty Images)
In more recent times we have the testimony of the street battles with the al-Qaeda followers of Abu Musab al-Zarqawi in Fallujah, Iraq, in 2006. A handful of fanatics with assorted weaponry manage to hold out against the US forces and Sunni tribal militias, while making the place an uninhabitable pile of rubble.
Rubble makes for handy makeshift defences. This is one of the great lessons of the battle of Stalingrad of 1942-43. Russian defenders used a half-demolished city as a fortress against the initially superior force of Von Paulus’s Army Group South.
In the Chechen war of 1994-96 Dzhokhar Dudayev’s nationalists used the same technique against superior Russian air and ground forces in Grozny: ruined buildings became formidable redoubts and crippled Soviet tanks and carriers barricades.
Far from the least consideration is the human presence in such a confused space, which will be populated by disguised fighters, confused fleeing civilians, frightened hostages and foreign NGO and charity workers.
The presence of more than a million and a half refugees underlines the need for a clear set of objectives for the different phases and the conclusion of the operation — in military jargon these are the phases and way points, and the culminating point and end state.
The first phases, according to informed sources, are to clear the northern part of the Strip down to a line south of Gaza City.
The Israeli command must then decide whether to occupy and hold this ground indefinitely. From there they must decide the end state, ultimately a decision for the Israeli government, and, no, doubt, its ally the United States.
Previous experience of Israeli ground operations against Hamas in Gaza is somewhat cautionary.
An Israeli tank in position near the Gaza border (Image: Getty)
In 2008, Operation Cast Lead saw an incursion of 15 days. In 2014, Operation Protective Edge lasted just under three weeks and cost the lives of 67 IDF soldiers, with 469 injured.
To make sense of the tactical and operational decisions now being taken for a ground operation, the IDF commanders and the government must set a strategic goal, and a final end state.
If the main aim, or centre of gravity in military speak, is the elimination of Hamas as a terror force, a long-term strategic aim must be set for the Palestinian question, as well as resolution of that scorched handkerchief of territory called Gaza.
Robert Fox is defence editor of the London Evening Standard and a regular television and radio commentator on military affairs
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