How difficult is invasion and occupation?

Israel’s military (the IDF) is currently contemplating a ground operation into Gaza. This means they will be sending troops into densely populated Palestinian areas with the aim of killing Hamas terrorists. The aim of this operation is, in the words of Prime Minister of Israel Benjamin Netenyahu, "destroying Hamas's military and governing capabilities." The plan seems to be to enter Gaza, release the over 200 hostages taken by Hamas, destroy Hamas bases, eradicate their military stockpiles, take out their leadership, and kill as many militants as they can. But this kind of warfare - an urban counterinsurgency and occupation operation - is one of the hardest, most taxing and complicated forms of warfare and can take ages. So what are the key challenges facing the Israelis?

Prepared Opposition - Hamas will have been well aware that when they entered Israel and started killing civilians that they would elicit a response from the Israeli government and armed forces. They were also probably aware that that response was likely to come in the form of an invasion and would have prepared accordingly. This means trapped buildings, suicide attacks, ambushes and blocked roads. They will also face car bombs, mines and civilian opposition. This will mean that any progress will be slow and costly for the IDF.

The Style of Warfare - This kind of fighting is tough and requires both patience and a lot of troops. Traditionally this kind of warfare requires a ratio of troops of ideally 10:1. This is due to the fact that as you move through a city of this type you need to leave in each cleared building enough troops to prevent it from being retaken by Hamas. Hamas probably has more than 20,000 troops but may have as many as 30,000. While the IDF have nearly 500,ooo troops in total it seems unlikely that they will have more than 100,000 troops ready to deploy within Gaza, according to estimates from urban warfare specialist Professor Anthony King of Exeter University. If we compare this to the Battle of Mosul in 2016-17, a situation with similar size, population and battle style, it took the Iraqi forces, backed by US and allied technology and support, more than nine months to retake Mosul from ISIS despite a 10:1 troop advantage (the Iraqis with approximately 110,000 troops to ISIS’ approximately 10,000 fighters). While the IDF is better trained than the Iraqi Military this operation does give us some sense of the difficulties that Israel might face if they seek to launch a full occupation invasion.

Civilian Complications - Gaza is one of the most geographically dense areas in the world. In total they have a population of over two million. According to Demographia Gaza City has a population density of 21,000 per square mile. The IDF will probably want to reduce civilian casualties where possible, if only to try to maintain international support (which might wane in the face of aimless killings of Palestinians). While the IDF have encouraged Palestinians to flee to the south of the Gaza Strip, and many have, many more remain - presenting a challenge for the invading soldiers. This is further complicated by Hamas’ deliberate placement of HQs and bases in civilian areas - the most prominent example being the suggestion that Hamas’ ‘de facto Headquarters’ are based under the Al-Shifa Hospital - the largest hospital in Gaza, in order to shield it from airstrikes. Similar claims have been levelled about bases under schools and apartment blocks. 

Another element of the civilian complications is the over 200 hostages which Hamas have taken and have begun to release regularly. The Israeli government has shown a tendency to place a high value on rescuing hostages and may fear their death if the IDF invades in force.

Tunnels - Gaza is well known for a highly complex tunnel system which lies under the city. This is a huge strategic problem for Israel. It negates to a significant extent Israel’s reconnaissance and surveillance and prevents the IDF from having a clear understanding of where Hamas strength and units are concentrated. The tunnels also allow Hamas to hide leaders, fighters and weapons caches which makes it harder for the IDF to achieve their aims of destroying the political and military structures and resources of Hamas. It also allowed quick and effective troop movement by Hamas allowing for surprise attacks and ambushes, not least from behind. This is also where many of the hostages are being kept which prevents easy retrieval thereof.

Hostages - Israel places a high premium on her hostages. After a raid in 2011 Israel agreed to the swapping of 1,027 Palestinian prisoners to win the release of one Israeli soldier. This is possibly part of the reason that the IDF’s actions on the ground have been less aggressive than expected. On the most practical level this means that before you advance or attack a building or blow up a tunnel you have to make sure none of the hostages will be threatened. The other obvious problem is that if you try to kill Hamas leaders or seize territory then Hamas can threaten to execute the hostages. This is one of the most difficult issues for Israel to negotiate in their actions in Gaza.

Israel has a highly trained and equipped military and, unless any of their other neighbours try and get involved, they should be able to overcome many of the challenges which face them. However, the speed and ease with which they can do this relies on a variety of factors including international support and the specific tactics which the IDF choose to employ. But one thing is certain - any military operation in Gaza will be exceedingly difficult for the Israelis.