Israel can take over Gaza in a matter of days. What’s next is up to them.

The surprise attacks conducted by Hamas against civilian targets in Israel have put the region — and potentially the world — into turmoil. At the time of writing, current estimates are that approximately 3,500 people have lost their lives between both sides. Given the current shutdown of basic services — electricity, water and fuel — in Gaza, the death toll in that area will rise independent of any military action. 

The late naval tactician Wayne Hughes admonished his students: “When there’s a war on, study the war.” The war has not started yet, but the mobilization of 360,000 Israeli troops and ongoing airstrikes combined with Israel’s government’s statements suggest an invasion is imminent.  It is not our intention here to moralize or discuss who is right or wrong — that is the role of politicians. Our purpose here is to simply make the best possible educated estimate of the outcome of the Israeli invasion, in the increasingly likely event an invasion happens.   

Determining the outcome of a war before it starts is a difficult business. As we frequently tell our own students, the data we have is the data we have; it is nearly impossible to know the on-the-ground truth.  

In this instance, the best thing that we can do is make a simile between this imminent conflict and the most relevant historical example: the U.S.-led invasion of Iraq in 2003. We assume that the Israeli Defense Forces are at least as effective as the U.S. ground forces in that conflict and that Hamas is no more effective than the Iraqi Army in 2003.    

We presume the Israeli Assault force will be about 360,000 troops, the size of the Israeli reserve mobilization. Estimating the size of Hamas — or any insurgent group — is notoriously difficult. Unlike regular military forces, irregular forces and insurgents are not full-time and fluidly blend in and out of the population as needs and strategy dictate. We conservatively estimate that up to 5 percent of the population of Gaza may be Hamas fighters, which would give Hamas a force of 105,000.  

How does this compare with the U.S.-led invasion of Iraq? The active combat phase of that conflict lasted from March 20-April 9, 2003; 20 days. The U.S. order of battle reports vary widely, but a Congressional Research Service report about the initial attack assessed a total of 340,000 U.S. troops in the region, although not all were actively engaged in combat. Iraq’s Army at the time was between 350,000-435,000 soldiers, distributed between regular soldiers, the Republican Guard and so-called “Elite” Republican Guard fighters.   

Before moving on to predictions, geography is important. The terrain of both Iraq and the Gaza Strip are more or less equal from a military perspective. Iraq has a total area of 437,000 square kilometers; Gaza has a total area of 360 square kilometers, or — to quote the CIA World Fact Book, twice the size of Washington D.C..   

Of particular note, the entire country of Iraq was not militarily important in the initial phases of the conflict. For ease of analysis, we will presume that only about half of Iraq was relevant in the battle. Some quick arithmetic shows that in the Iraq war, the coalition was able to take approximately 11,000 sq km per day, just smaller than the size of Connecticut. Alternately, this could be seen as gaining control of approximately 30 times the area of Gaza per day. U.S. service members suffered a total of 137 casualties (from all causes) in March and April of 2003. On the other side of the battle, Iraqi Army casualties are estimated somewhere between 4,900 and 6,400.   

It is noteworthy that several Iraqi formations surrendered en masse. In that war, the US took active measures to allow surrender and avoid civilian population centers. Therefore, it is perhaps more useful to use the average number of Iraqi fighters pacified per day (which includes surrender) as a metric. This is approximately 18,000 – 22,000 Iraqi fighters removed from combat per day.  

How does this apply to Gaza?  

The Israeli invasion force is roughly the same size as the coalition forces in Iraq. The Hamas opposition is (assumed) to be one-third the size of the Iraqi Army. Regardless of size, Hamas is not as well equipped (in the conventional sense) as the Iraqi army with tanks and air power. The Israeli Defense Forces maintain a strong advantage in both offensive airpower and air defense, as well as non-material factors such as training and organization.  

It is clear from even a casual look at this comparison that depending upon their strategy, the Israelis will be able to defeat Hamas within days. The limiting factor will most likely be the speed at which their armored columns can advance.  

Casualties in Gaza will be driven by Israel’s tactics, as we discuss below.  

The final result will be determined by Israel.   

Ultimately, the outcome of this conflict will be up to Israel; it will depend almost wholly on its strategy, which includes how much rhetoric around vengeance translates to action on the ground. Contingent upon this strategy, IDF casualties will likely vary between some number below 200 and the mid-thousands in a period between a few days and as long as a month. Casualties within the Gaza Strip itself will vary dramatically — once again contingent on Israel’s strategy — and at press time, we would believe any number proposed.    

Specifically, if Israel engages in urban combat, fighting house to house, this will both lengthen the conflict and almost certainly increase IDF casualties. The effect on non-combatants compared to alternative actions is unclear. If, conversely, Israel uses its aforementioned overwhelming advantages, particularly in air and armor, and chooses to raze Hamas strongholds rather than to fight them, Israeli casualties will be reduced. The impact on non-combatants — compared with other urban conflicts — is unclear.  

Ultimately, the outlook for Hamas — at least within the Gaza Strip — is dire. They will almost certainly be defeated. The result for Israel will almost certainly be a tactical victory, at least in the immediate to short term. The strategic ramifications for both Israel and the rest of the region are unclear, and — as everything else — dependent upon Israel’s strategy.      

Harrison Schramm is a retired naval officer and statistician.  He splits his time between his own statistical practice and teaching at the Naval Postgraduate School. He is the past vice president of the Military Operations Research Society.   

Regan Copple is a defense analyst and wargamer whose interests lie at the intersection of human decision-making, analytics, and public policy

The views expressed in this piece are solely those of the authors.