A new report in the New York Times sheds light on Hamas's meticulous underground warfare tactics, revealing the intricacies of their tunnel network and explaining the difficulties faced by the Israeli Defense Forces (IDF) in countering them.

The report, published Monday, details a Hamas "combat manual" dating back to 2019, discovered by the IDF during the current Gaza war. The manual, dubbed "The Underground Combat Guide," outlines Hamas's meticulous preparation for subterranean warfare, designed to withstand prolonged conflict and slow down Israeli ground forces within the dark tunnels.

The manual provides detailed instructions on concealing tunnel entrances, using compasses and GPS for navigation, and entering and moving efficiently within the tunnels. It also highlights the importance of blast-resistant doors, installed to protect the network from bombs and Israeli soldiers.

The document reveals that just one year before the "Operation Breaking Dawn" on October 7th, Yahya Sinwar, then Hamas leader in Gaza, approved the expenditure of $225,000 for these doors, bolstering the tunnel network against airstrikes and ground assaults.

The guide further describes how fighters navigate in the dark, move stealthily, and utilize automatic weapons in confined spaces for maximum lethality. It emphasizes the need for night vision goggles with infrared capabilities and instructs fighters to move with one hand on the wall and the other on the weapon of the fighter in front of them.

Field commanders are also tasked with meticulously timing the movement of their fighters between underground points, down to the second.

While Israeli officials were aware of Hamas's extensive tunnel network before the war, they acknowledge its sophistication and scale exceeded their expectations. They now recognize that Hamas was actively preparing for this confrontation.

Initially, officials estimated the tunnel network to be around 400 kilometers long. However, they now believe it to be more than twice that length. The report also highlights the difficulty of destroying these tunnels, with a single section taking up to 10 hours to demolish, according to a senior Israeli officer specializing in tunnel warfare.