The U.S. Just Dropped the ‘Mother of All Bombs’ in Afghanistan. But What Is That?

The United States on Thursday dropped “the mother of all bombs,” the largest non-nuclear bomb it has ever used in combat, on an ISIS tunnel and cave complex in eastern Afghanistan.

The bomb, officially called the GBU-43/B Massive Ordnance Air Blast (MOAB), was dropped from a MC-130 aircraft in the Achin district of Nangarhar province, Pentagon spokesman Adam Stump said, according to the Associated Press. The target was near Afghanistan’s border with Pakistan.

President Donald Trump said Thursday the bombing was a “very successful mission,” according to Reuters, and he touted the mission as evidence of a stronger foreign policy under his administration. It was not immediately clear how much damage the bomb did, how many militants were killed, or whether any civilians were killed.

Here’s what you need to know:

What is the bomb?

The GBU-43 is a GPS-guided weapon that weighs an enormous 21,600 pounds, according to an article from the Eglin Air Force Base. Each one costs $16 million, according to military information website Deagel.

During testing in the early 2000s, it created a mushroom cloud that could be seen from 20 miles away, according to the Air Force story.

Why was it developed?

The MOAB was designed in 2002 as a replacement for the BLU-82 Daisy Cutter, according to the Air Force article. Its purpose was initially to put pressure on former Iraqi dictator Saddam Hussein.

“The goal is to have the pressure be so great that Saddam Hussein cooperates,” said then-Defense Secretary Donald Rumsfeld in a 2003 interview, according to the Air Force article. “Short of that — an unwillingness to cooperate — the goal is to have the capabilities of the coalition so clear and so obvious that there is an enormous disincentive for the Iraqi military to fight against the coalition.”

Has it been used before?

The bomb was sent to the Middle East in 2003, but it had never been used before this week.

How many does the U.S. have?

The U.S. military says it has 20 MOAB bombs and has spent about $314 million producing them, according to CNBC.

What kind of destruction does it cause?

While not all details from Thursday’s blast have been made public, the bomb is very powerful. “What it does is basically suck out all of the oxygen and lights the air on fire,” Bill Roggio, of the Foundation for Defense of Democracies, told Air Force Times. “It’s a way to get into areas where conventional bombs can’t reach.”

While it was initially intended to deter U.S. opponents, this week’s strike marks a change to using the weapon as an active tool in fighting ISIS. The use of the MOAB in the Nangarhar province indicates the U.S. still considers ISIS a threat in the area.