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Urban warfare has produced some of the most brutal battles of the 21st century. In Fallujah in 2004, US Marines went house-to-house in a struggle with Iraqi insurgents that left hundreds of civilians dead.
The US has confirmed that it is sharing “20 years of lessons learnt” with the Israelis as they face up to Hamas’s drones, booby traps and network of tunnels in Gaza.
“Soldiers will be asking, and commanders should be asking, what it is that you want to achieve with this mission exactly,” said Frank Ledwidge, who served as a UK military intelligence officer in Iraq and has written books criticising the conduct of Britain’s Middle East wars.
“The elimination of Hamas won’t do. That’s an operational objective. What is it that strategically you’re going to do?”
At a tactical level, Mr Ledwidge believes it is not just Israel that will be looking to learn the lessons of previous urban combat.
Hamas too “will have looked at the vulnerabilities, why it was that ISIS lost or were operationally defeated on the ground”, Mr Ledwidge told The National. One lesson, he said, would be for Hamas fighters to take “no fixed positions”.
“They will have learnt the ineffectiveness of vehicle-born IEDs [improvised explosive devices]. They’re very frightening but the Iraqis worked out ways to deal with them and the Israelis certainly will.
“However, the effectiveness of massive IEDs to neutralise armour and tanks is a lesson to be drawn not only from ISIS but also battles like Fallujah.”
US forces reported finding 26 IED factories in Fallujah, where dozens of American soldiers, hundreds of civilians and thousands of militants were killed during two battles. The hostilities were triggered by the killing and mutilation of four US contractors in early 2004, with Marines eventually entering the city to root out Al Qaeda militants there.
In Mosul it is estimated that more than 10,000 civilians may have died, some of them killed while trying to flee the battle between Iraqi forces and ISIS.
ISIS turned to urban warfare tactics such as “mouseholing”, which involves blowing holes in walls so that fighters can move between buildings unseen from the outside.
Lloyd Austin, the US Secretary of Defence, said the battle for Mosul might prove to have been easier than a campaign in Gaza, where he predicted that the Israelis would face “a lot of IEDs, a lot of booby traps”.
Defence analyst Sam Cranny-Evans said it was “easy to draw comparisons” with battles such as Mosul or Raqqa, another ISIS stronghold in Syria that was captured by US-backed forces in 2017.
“The key point really is the Hamas willingness to defend and hold its ground,” he said. “There have been a number of encounters between Israeli forces and Hamas in the past, and Hamas has displayed increasing capabilities over time.”
Hamas has the extra advantage of drones and rocket-launched grenades, making the battle for Gaza “the first war where the insurgents are going to have some significant air power”, Mr Ledwidge said. Hamas is believed to have used drones to sabotage Israeli defences during its attack on October 7.
Carlo Caro, a military analyst, wrote in a commentary for the Henry L Stimson Centre that combatants in urban warfare can find they “win the battle but lose the broader conflict”.
“Battles such as Hue in the Vietnam War and Fallujah in the Iraq War demonstrate that achieving victory in an urban conflict does not necessarily translate to success in the larger war,” he said.
Russia’s siege of Mariupol similarly bogged down its forces and made the city a symbol of Ukrainian resistance, making its eventual capture something of a pyrrhic victory for the Kremlin.
The warren of tunnels at the Mariupol steelworks are a parallel to the Hamas-built tunnels in Gaza. Israel believes entrances are hidden near schools and hospitals and accounts from hostages say they were held in the underground labyrinth, increasing the dangers to civilians.
Israel told 1.1 million people to leave northern Gaza before it invades, but the order was condemned as impractical and as many as 400,000 people are thought to still be there.
For civilians and local infrastructure, the repercussions of an Israeli assault on Gaza “could be far more catastrophic” than in Fallujah or in Grozny during the Chechen wars, Mr Caro said.
In Fallujah, an initial battle in early 2004 was halted amid pressure on the US to limit harm to civilians. Israel is likewise under immense scrutiny over its actions in Gaza.
Mr Ledwidge said Hamas would try to get invading forces bogged down in another long conflict echoing the bloody battles of recent years.
The "primary worry" for Israel's allies, he said, is "let’s get a plan together we think we can make work, so we don’t get to a point like we did in these other places”.