As ISIS mortars began to rain down onto the advancing convoy of Kurdish commandos in October, three trucks raced to slam into their Humvees and waylay their assault on Mosul. A Kurdish gunner took aim at the first bomb-laden truck with an anti-tank missile and fired.
ISIS fighters are relying on suicide attacks to decimate and demoralize the Iraqi and Kurdish forces working to uproot them from northern Iraq’s largest city, a difficult effort where progress is often measured in blocks. As of Tuesday, ISIS has deployed at least 208 suicide bombers — most but not all in vehicles — over a 56 day span. Researchers say it is the largest deployment of suicide attackers in modern history, since the kamikaze attacks used seven decades ago by Imperial Japan.
“They’ve got the numbers of willing bombers and experience to turn these attacks into a sort of close air or artillery support for an army that lacks planes to support their conventional operations,” said one Western security advisor working in the region, who asked for anonymity out of concern for his personal safety. “And it’s bloody effective.”
“Call them a poor man’s JDAM, if you will,” he added, referring to the GPS-guided bombs used by fighter jets.
And although the numbers haven’t reached the industrial scale of that Japanese effort, ISIS has long favored suicide attacks as a force multiplier to support conventional military operations and the group appears to have a deep supply of fighters willing to incinerate themselves by piloting the explosive-laden cars and trucks into enemy front lines.
"It's not easy for us. They are suicidal," Omar Salem, a 23-year-old gunner on the Kurdish convoy, had warned the night before the October attack, when a BuzzFeed News reporter and photographer accompanied the unit as it assaulted ISIS defenses outside northern Mosul. "You can't expect what they're going to do. There is no space for failure."
During that assault on Mosul the next day, the anti-tank missile struck the first suicide truck as it sped across a dusty field, detonating it in a blast whose force shuddered the armored Humvees in the Kurdish convoy. Within minutes a second truck bomb, this time covered in a makeshift armor of thick metal plating impervious to gunfire, was on its way, only to be detonated by another anti-tank missile. Later, the soldiers also destroyed a third bomber.
Guided anti-tank missiles are the most effective means to destroy car bombers, and one the Kurds have lobbied for after ISIS’ 2014 seizure of Mosul.
A few weeks later, on a visit to Iraqi Special Forces aligned with the Kurds – while nominally part of Iraq, the Kurds operate their own government and military forces largely independently of the central government — soldiers described car bombs, or vehicle-borne improvised explosive devices in military jargon, as the single biggest threat and cause of casualties in the Mosul assault.
These terrifyingly effective weapons are an obsession for the troops who call in U.S.-led airstrikes. These forward air controllers are often posted close to battle to rapidly radio in US and coalition airstrikes on suspected bombers.
A top commander with Iraqi Special Forces calls the deployment of scores upon scores of the attackers as a critical part of ISIS’ defensive plan for Mosul that has forced the attacking coalition to move much more slowly as the fighting had shifted to the densely populated urban cityscape where sight lines — and the effectiveness of overhead air support — are much more limited.
"We were like the rat and they were the cat," Maj. Salam Hussein, the commander of the special forces unit leading the charge in Mosul, said one night after being menaced by a car bomb team most of the day.
ISIS is the latest group to seize on the car bomb as a weapon. The tactic dates back about a century, to when a horse-drawn carriage bomb exploded on Wall Street in New York. To be sure, some historians claim Armenian nationalists might have used one in a 1905 assassination attempt against Ottoman Sultan Abdul Hamid II in Istanbul. As a weapon of irregular warfare, the suicide car or truck bomb was popularized by Lebanese militants in the early 1980s and quickly adapted by militants attempting to overcome an opponent’s conventional military advantage.
“What we’ve seen over the last four decades is the combination of car bombs – which are an old way to set off a bomb in a crowded area — with the suicide attacker who guides it into targets making it much more effective,” said the security advisor, a former British Special Forces veteran currently advising a Middle Eastern government in counter-terrorism operations.
“While it’s an instrument of terror — and a fairly common one at that — what’s new about the Mosul operation is an extension of how Daesh had started using them back in the earlier days of the Syrian civil war and even when they were known as al Qaeda in Iraq fighting the Americans and British forces,” he said, using an Arabic slang term for ISIS, going on to add to add how they’re used to target advancing forces
A UK-based insurgency analyst says that ISIS stopped announcing its car bombings at the outset of the Mosul offensive, which could be a way to mirror the operational secrecy used by conventional militaries or just be related to the sheer volume of the attacks.
“When the Mosul operation first began, at the beginning of the campaign [ISIS] weirdly wasn’t releasing the names and photos of the attackers,” said Charlie Winter, based at the International Centre for the Study of Radicalization at Kings College, London, who tabulated the tally of Mosul suicide attacks by monitoring an array of ISIS-related social media and messenger feeds. Winter isn’t certain about why the group – famous for documenting its operations as part of its broader media strategy – would change course for the initial phase of its most important battle.
“I wish I knew why that was,” he said. “But it was really striking how they went off the announcements and then a few weeks later went back to releasing details.”
According to Winter’s research, in the early days of the ISIS defense only one in ten attackers was identified, and even less often eulogized, which is traditionally a key component to the ISIS media operation. That ratio recently shifted to about three out of every five attackers receiving a full eulogy and attention.
One thing that’s clear, Winter said: ISIS is relying heavily on local Iraqi and Syrian fighters in the claimed suicide attacks, a shift for the group which has used foreign volunteers more often than locals, in part because of a lack of military experience, or in many cases, local language skills in Arabic or Kurdish, that make the foreign volunteers a liability in conventional fighting.
“As they returned to announcing the attacks after the initial phase, what we have seen is what appears to be a heavy use of localized kunyas [Arabic nicknames that often include a geographic description of where the person is from], so we saw more Anbari [from Iraq’s Anbar province], Halabi’s [from the Syrian city of Aleppo] and the like, driving home that the locals are doing the attacks.”
This, Winter explained, is likely because the group has taken great lengths to argue that it’s defending its caliphate using people from the area under attack by “outsiders,” so “it added credibility and legitimacy to the argument that it is protecting its own territory.”
In terms of the data Winter has collected, local — in this case just Iraqi — attackers are conducting more than half the suicide operations, usually VBIED in nature, with the other half scattered among a slew of foreign countries including Syria, Egypt, Kurdistan, Russia, Dagestan, Chechnya, Morocco, Tunisia, France, Uzbekistan, United Arab Emirates, and Ireland.
This strategy has impeded the Iraqi coalition’s advance across the battle-ravaged city.