Afghan defense officials announced Friday that 36 ISIS fighters were killed by a U.S. air strike on a tunnel and cave complex, with the possibility of a larger death toll. The strike was carried out on Thursday with a GBU-43 bomb, nicknamed the “Mother of All Bombs,” marking the first time the weapon has been used in combat operations.
The GBU-43, or “MOAB”—Massive Ordinance Air Blast bomb—is a 21,000 pound weapon and is the largest satellite-delivered, air-delivered weapon ever made, according to GlobalSecurity.org. It is an updated version of the infamous “Daisy Cutter” bombs used in the U.S. invasion of Afghanistan following the 9/11 attacks in 2001.
The strike took place in Achin district of Nangarhar province in eastern Afghanistan, near the troublesome border with Pakistan, and is known to be an area where ISIS fighters operate.
In a press conference on Friday, the commander of U.S. Forces-Afghanistan, Gen. John Nicholson, explained the military’s use of MOAB. “The enemy used these tunnels and minefields to move around the battle field and protect themselves from attacks from Afghan and U.S. forces. This was the right weapon against the right target.”
A spokesperson for the Afghanistan Ministry of Defense added that the tunnel complex was as deep as 40 meters in some areas, making it difficult for conventional weapons to penetrate.
Afghanistan’s chief executive, Abdullah Abdullah commented on his official Twitter account that the strike had been carried out in coordination with the Afghan government, and stressed the operation was carried out carefully.
“Many families had long been been displaced from the area due to ISIS brutality. Gov't also took great care to avoid civilian harm,” he wrote.
IS commander Siddiq Yar was among those killed, presidential spokesman Shah Hussain Murtazawi told the BBC.
The Cipher Brief spoke with Lt. Gen. (ret.) David Deptula who, as commander of the combined air operation center during the opening stages of Operation Enduring Freedom in Afghanistan in 2001, orchestrated the use of MOAB’s predecessor, the BLU-82, or “Daisy Cutter”.
He agreed the use of the weapon was appropriate and effective, given the battleground assessment.
“It was used in a terrain area that channelized the blast and effectively crushed and collapsed a sequence of caves and underground hiding locations that Islamic state fighters were using. It was in an extremely remote location, so civilian casualties weren’t an issue,” Deptula told The Cipher Brief. “Basically what the weapon allowed the commander in the field to accomplish was the same effect in seconds that a large scale ground force might have taken a month or more to achieve with a high probability of casualties.”
Deptula went on to explain the reason MOAB was used in this particular case was because it can achieve “overpressures” that smaller, individual weapons simply can’t accomplish.
“Quite frankly, it’s got a blast radius that extends to a mile. A thousand-pound bomb doesn’t do that. They have a much, much more limited blast effect, less than a thousand feet. So just because 21 1,000 pound bombs equals 21,000 pounds of explosives, the effect is much different.”
Responding to a question if he foresaw the future use of MOAB, Deptula was quick to point out the weapon was originally developed prior to Operation Iraqi Freedom in 2003, but was never used in battle at that time because the none of the conditions where its use may have been applied showed up.
“In this particular set of circumstances, the conditions that fit very well appeared, and it was used, and that will be the case in the future. They are looking for the right weapon, right place, right time. If these conditions come up in the future, they will be used. If they don’t, it won’t. It’s that simple.”
The bombing in Afghanistan comes nearly a week after the U.S. launched missiles at a Syrian airbase in retaliation for what the U.S. claims was the Assad regime’s use of chemical weapons against its civilians.
When asked at a White House event, on Thursday, if he personally authorized the strike, President Donald Trump responded, “What I do is I authorize my military. We have the greatest military in the world, and they have done a job, as usual. So we have given them total authorization, and that is what they are doing.” The President referred to the strike as “another successful event.”
During a State Department press briefing, spokesperson Mark Toner said Thursday’s strike was part of an ongoing military effort against terrorist groups operating in Afghanistan, including ISIS, the Taliban, and al-Qaeda affiliates.
The ISIS branch in Afghanistan – also known as ISIS-K or Korasan group – is comprised of former members of the Afghan and Pakistan Taliban.
“Let me be clear: we will not relent in our mission to fight alongside our Afghan comrades to destroy ISIS-K in 2017”, said Gen. Nicholson.
Verdi Tzou is a national security web editor at The Cipher Brief.