Military analysts and strategists mostly refer the warfare in terms of three domains Air, Land, and Sea. In each of these domains, the combatant of one adversary struggles to defeat their opponents to open a path to their political objectives. However, there is a fourth domain that is mostly overlooked by analysts. It has been used in the past time as a clandestine approach towards the opponent. It has also been utilized recently by some groups against powerful conventional forces on Earth.

The forgotten domain is the use of underground tunneling, to establish a subterranean axis to advance while this strategy has been often used as a decisive effect throughout history.

The ongoing war in Gaza which started after the attack of Hamas on Israel on 7^th October, converted into the fourth domain of warfare (Tunnel warfare). According to the reports, more than 20,000 people have died in Gaza, including children and women, since the war began. However, the “Gaza Tunnels” are not new, they date back to the 1980s. In the past, these tunnels were used for smuggling goods such as electronics, construction materials, fuel, weapons, etc.

Gaza which is 41 km long and only 6 to 12 km in width, around 500 km long tunnels were established by the Hamas leadership. While these tunnels are 60 to 90 ft underground. According to the reports, the number of tunnels that are currently operational is 1300. While the IDF (Israel Defence Force) claimed that they destroyed some tunnels of Hamas.

Normally, the Hamas leaders use these tunnels for counterattack against Israel while they also use these tunnels for smuggling of weapons and other goods. Mostly, these tunnels open under the construction areas while also they have access to inside the Egypt border to import goods and other things from Egypt. Inside these tunnels, all the facilities for survival are operational such as hospitals, stores, etc.

In 2014, the IDF discovered a tunnel which were completely made from cement from all sides while that tunnel was so wide even a small truck could travel in it. Recently, the Hamas leadership shared a video where a vehicle went inside the tunnel, driven by the brother of Gaza leader of Hamas Yahya Sinwar. So, we can analyze from this video how modern these tunnels are.

Raphael S. Cohen, a senior political analyst and director of the Strategy and doctrine program at Rand Corporation argued that the IDF is using modern technologies to detect the Hamas tunnels in Gaza including acoustic sensors or colored smoke grenades.  He argued that it is really hard and difficult to get the full picture of these tunnels because you are running against the limit of technology here.

Moreover, the IDF also targeted the Al-Shifa hospital by arguing that the most and main network of tunnels is present here inside the hospital but they didn’t provide any proof of it while hundreds of people including children died in the attack that happened in the mid of November.

Recently, on 27 December, the IDF discovered a tunnel near the Erez Border crossing, which was used by the Hamas leadership against Israel on Oct 7^th attack. The tunnel is 2.5 miles long and extends to Gaza. It was seen in an image that the tunnel was made from heavy constructive materials and cement. It is so wide that a small truck can travel in it.

However, after the discovery of these tunnels, the Hamas leadership shared a video clip on social media of 47 seconds, where this tunnel could be seen in the video where some hostages were held in the tunnel after the 7^th Oct attack. They gave a message to the IDF that the tunnel had completed their purpose for which it had been made and after the attack, the tunnel was closed down by the Hamas.

However, Israel can attack the tunnels across Gaza but the main difficulty is, that all the hostages are held in the subterranean network. This can be difficult for Israel to attack its people inside Gaza. On the other hand, Israel which is considered one of the top technological states, has yet to fail to discover all the tunnels of Hamas.

The Israeli forces were trialing pumping the seawater into the underground network which is against humanity and one of the elements of the crime of genocide.

According to the US military academy of West Point, there are 1300 tunnels inside Gaza which need 1.5 cubic meters of water to fill them. However, the environmental consequences would be far-reaching after this move in Israel. It will ruin life in Gaza and will leave no drinking water in Gaza while also deteriorating agriculture.