The US can paint a vivid picture of civilian slaughter. During the eight-month siege to liberate Mosul from Islamic insurgents, as many as 10,000 people were killed, including at least 3,200 civilians from air strikes, artillery fire or mortar rounds between October 2016 and the fall of Islamic State in July 2017, according to an Associated Press investigation.

About the same number of civilians were killed or taken hostage by militants and used as human shields as they fled the city.

They were keenly aware of efforts to set up humanitarian corridors and decisions to pause operations while civilians were warned to move away.

So as they are speaking to their Israeli counterparts on an almost daily basis, they are sharing advice on the challenges of urban warfare, the threats of booby traps and roadside bombs and the drive to protect the innocent while rooting out insurgents hidden in schools, mosques and homes.

“Sharing our 20 years of lessons learned is occurring up and down the chain,” said US Navy Captain Jereal Dorsey, the spokesman for Brown.

Underscoring that priority, the US has sent a team of military advisers to Israel, including Marine Corps Lieutenant General James Glynn, who helped lead special operations forces against Isis.

Glynn, who also served in Fallujah during some of the most heated urban combat there at the height of the Iraq War, will be able to advise the Israelis on how to mitigate civilian casualties in urban warfare.

“These officials, to include General Glynn, have experience when it comes to urban combat,” Ryder told reporters Tuesday. “They’re in there temporarily with their military expertise to just go through and discuss some of the hard questions that the IDF should consider as they plan various scenarios.”

In discussions last week with Israeli defence and government leaders in Tel Aviv, Austin recalled his experiences heading US Central Command during the first two years of the campaign to defeat the Isis. He talked about lessons learned, including the realisation that the world is watching, officials familiar with the talks said.

Austin was blunt both publicly and privately that as Israelis plan their military operations, including any ground assault into Gaza, they must take into account the safety of civilians.

“There are some lessons learned that we will be more than happy to share with our allies here in terms of operating effectively in dense urban terrain, creating safe humanitarian corridors, making sure that we’re thoughtful about how we shape the battle and making sure that our objectives are well defined,” Austin told reporters.

A RAND report released last year found that while the US emphasised the need to minimise civilian harm in the devastating 2017 siege to liberate Raqqa, Syria, there were thousands of casualties.

It recommended that the US military adjust its planning, training, targeting and use of weapons in order to better avoid widespread civilian deaths and damage.

Retired US Army General Joseph Votel, who took over US Central Command in 2016 when Austin retired and oversaw the operations, said the most important message for the Israelis – which has been delivered by Austin, Secretary of State Antony Blinken and President Joe Biden – is that it’s not what Israel does in its pledge to destroy Hamas, but how the military does it.

“How you orchestrate this campaign really matters,” said Votel. “And they have to do this in a way that reflects values and the concern for innocent Palestinians who themselves are being held hostage by Hamas.”

He added that there are many similarities and some key differences between those missions and a potential assault into Gaza.

Hamas, he said, is better armed, with more sophisticated explosives and other weapons supplied by Iran. And the labyrinth of tunnels under Gaza is far more developed and lengthy than those seen in Raqqa.

Militarily, he said, Israel is seeing a more sophisticated and better armed opponent than Isis was in Syria and Iraq.

“There’s a difference between being dug in, going to ground and what we are seeing in Gaza, which is an underground architecture that connects different parts of Gaza and allows people to move supplies, people and other things, and enhance critical functions underground,” said Votel. “I don’t think Isis got to that particular level of sophistication.”

He said the US and coalition allies had more time to prepare for the battle to retake Mosul. And he said that as the coalition moved down the Euphrates River, it stopped and paused operations a number of times in order to meet with local tribal leaders and try to get innocent civilians out of the line of fire.

The brutality of it all is another element Austin recalls, as well as the need to stop militants even as they are embedded deeply into urban civilian areas.

“In countering Isis I felt as if we were staring evil in the eye,” Austin said. “It was truly evil. And what we’ve seen from Hamas, it takes that evil to another level. And so that’s the first thing that we need to remember and consider.”