The battle for the city of Mosul in northern Iraq marked the largest combat operation anywhere in the world in nearly 15 years. The scale, duration and particularly the intensity of this military campaign, was a facet of warfare that had not been seen in decades — making it easily comparable to many military campaigns that had taken place as far back as the second world war.

The operation commenced on October 7th of last year, when a coalition ground force of over 100,000 personnel converged on the city of Mosul from five different directions. This ground force was mostly comprised of Iraqi military and police, but also had many Shia Islamic militiamen, as well as a few U.S. advisers operating within it.

Some of the anticipated tactics and technologies that the coalition ground force immediately encountered upon entering the combat arena had been the widespread use of IED’s, suicide bombers, direct and indirect small arms fire, well-entrenched snipers and civilian human shields.

This battle also introduced a few tactics and technologies that were not expected, including extensive car bomb production facilities, weaponized commercial drones, elaborate tunnel systems, strategic destruction of critical infrastructure such as bridges, and even the demolition of the centuries old al-Nuri Mosque by ISIS militants, where the Caliph of the Islamic State Abu Bakr al-Baghdadi first announced the ISIS caliphate.

The battlefield in this campaign involved a very dense and hard to maneuver landscape that placed a new emphasis on maneuver warfare. It quickly became apparent how important it is to take this factor into account so as to avoid unexpected and disadvantageous, dismounted engagements in the confines of areas like Mosul.

The thousands of civilians stuck in the middle of the engagement between coalition forces and ISIS militants had enabled ISIS fighters to force these civilians into captive participance as human shields, allowing for these militants to freely maneuver around the battlefield with limited concern for being fired upon by coalition forces.

The Islamic States unique and unrelenting use of car bombs, at a rate of 5 per day at the height of the campaign, and nearly 1000 attacks total over its duration, made the production facilities of these unconventional weapons a high priority target for coalition airstrikes. Targeted airstrikes were responsible for destroying over 100 of these production facilities; a staggering number that no military planners had anticipated when entering into this campaign.

Another unanticipated technology certainly worth noting was the use of drones by both the Islamic State and coalition forces. The deployment of commercial drones had been a fairly common battlefield occurrence since the beginning of 2016, mainly being used for the purpose of surveillance and reconnaissance. During the battle of Mosul however, these drones entered a new phase in the area of weaponization, and were equipped with 40mm grenades that had been rigged with rudimentary drop-flight stabilizers. These kinds of weapons gave the Islamic State a quasi-airforce capability at relatively little cost, and this technology wreaked havoc and terror on coalitions ground forces throughout the campaign. 

The coalitions air campaign had played a critical role in helping to defeat the Islamic State in the fight for Mosul. The use of increasingly refined GPS precision guided bombs, and superior target identification and intelligence, made effectively targeting well-entrenched ISIS fighters without the need of risking direct contact of coalition ground forces, a preferred strategy when the conditions permitted. This helped to significantly mitigate the casualties of both civilians and coalition forces, and bring a quicker end to the campaign. 

The battle for Mosul marked the end of a three year occupation by the Islamic State, and had been the largest defensive campaign yet in the war against ISIS. The 8 month duration of intense, non-stop combat yielded a substantial amount of information on how a conventional military force should be fighting against an asymmetrical adversary on today’s battlefield with the technologies and tactics that are widely available today.

The battle for Mosul is certainly going to become a focal case study for military leaders and strategists in the decades to come. This battle will be sure to result in new tactics and technologies that will eventually be developed and implemented in future battlefields around the globe.