April 13, 2017, will be remembered by some as the day when Donald Trump dropped the "mother of all bombs" on ISIS in Afghanistan. Specifically, the MOAB was dropped in Nangarhar Province — a name that you've heard before, if you've been following American military operations in Afghanistan. Specifically, you might have heard of Nangarhar Province soon after the 9/11 attacks — because at the time Osama Bin Laden was hiding out in the Tora Bora region of the province.
Nangarhar is quite mountainous, making it difficult to maneuver — so it's often been used as a hideout by groups like al Qaeda and ISIS. It's located in the eastern part of Afghanistan, right on the border with Pakistan. The MOAB was dropped over the Achin district of Nangarhar, where ISIS has centered its activities in Afghanistan since 2015.
According to White House Press Secretary Sean Spicer, the bomb targeted "a system of tunnels and caves that ISIS fighters used to move around freely, making it easier for them to target U.S. military advisers and Afghan forces in the area." The bomb, which detonates in the air, is meant to send a shock wave that can destroy tunnels, and the blast radius is a mile wide.
The Nangarhar Province has a lot on its hands right now, even if American forces have just destroyed an ISIS hideout. Nangarhar is a prime location for growing opium, and the Taliban has long been able to profit off the drug trade in the province. However, it's still unclear as to whether ISIS is doing the same; in fact, some analyses have shown that they could be getting rid of the poppy fields that produce opium. Still, Afghanistan (and Nangarhar specifically) is a center of the global opium trade, which provides a constant potential revenue source for terrorist groups.
The branch of ISIS in Nangarhar consists of mainly fighters from Uzbekistan and Pakistan. The border between Pakistan and Afghanistan into Nangarhar is rather porous, so it's a good place for terrorist groups to smuggle people and weapons across border. Although U.S. authorities have reported that ISIS had strengthened their presence in Nangarhar with various weapons and protections, they have not had an easy time spreading outside of that province and a few neighboring provinces in eastern Afghanistan. The American military has already carried out hundreds of airstrikes against ISIS targets in Afghanistan in 2017, leading to a large reduction in their territory.
The military is currently gathering information on what damage the MOAB caused, but if the strike did indeed achieve its goal, this could have seriously damaged ISIS' presence in Afghanistan.