When the so-called Mother of All Bombs was first tested, in 2003, the largest conventional weapon in the United States arsenal set off a mushroom cloud visible for twenty miles. The potential damage from the twenty-two-thousand-pound bomb was so vast that the Pentagon ordered a legal review to insure that the device wouldn’t be deemed an indiscriminate killer under the Law of Armed Conflict, the body of law that regulates behavior during wartime. The MOAB was compared to a small nuclear weapon. It’s so large that no U.S. warplane is big enough to drop it: it has to be offloaded from the rear of a cargo plane, with the help of a parachute.

“Although the MOAB weapon leaves a large footprint, it is discriminate and requires a deliberate launching toward the target,” the Pentagon report concluded. “It is expected that the weapon will have a substantial psychological effect on those who witness its use.”

Fourteen years after it was deemed ready to use, the U.S. unleashed the MOAB for the first time in combat on Thursday, at 7:32 P.M., against an ISIS affiliate in Afghanistan’s eastern Nangarhar Province, along the border with Pakistan. In Washington, the White House press secretary Sean Spicer said that it “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.”

ISIS-K has complicated the sixteen-year war in Afghanistan since it emerged, in 2015, and distracted from the long-standing mission of fighting the Taliban. (The “K” stands for Khorasan Province, a historic area that includes parts of modern-day Afghanistan and Pakistan.) It is blamed for the first U.S. combat death in Afghanistan this year, when Staff Sergeant Mark De Alencar, a Green Beret and a father of five, was killed in the same area of Nangarhar last week. The MOAB struck the epicenter of ISIS operations.

The GBU-43 Massive Ordnance Air Blast (MOAB) bomb, in an undated photo. PHOTOGRAPH BY ELGIN AIR FORCE BASE / HANDOUT VIA REUTERS PHOTOGRAPH BY ELGIN AIR FORCE BASE / HANDOUT VIA REUTERS

There are few places where the GBU-43 Massive Ordnance Air Blast, as the bomb is officially known, can be used, because of the breadth of its impact and the danger it poses to civilians. It does not penetrate the ground, instead setting off a massive pressure wave and giant fireball. The cave complex used by ISIS was in a remote and rugged area of mountains and gorges. The use of a MOAB means Afghan and U.S. troops, which launched a mission in the Nangarhar region last month, did not have to fight in areas where they are at a distinct disadvantage.

“This was the first time that we encountered an extensive obstacle to our progress,” Nicholson said on Friday. “It was the right time to use it tactically against the right target on the battlefield.” Retired Major General James (Spider) Marks told me, “It allows the coalition to do significant damage without significant risk to our Special Forces.” Afghan military officials said that at least three-dozen militants had been killed. Nicholson said on Friday that U.S. and Afghan forces were at the site of the bomb and found no civilian casualties.

The U.S. decision to drop the bomb was striking for several reasons. America’s biggest non-nuclear bomb–which costs sixteen million dollars, and three hundred million dollars to develop—was used on one of the smallest militias it faces anywhere in the world. ISIS-K is estimated to have only about seven hundred fighters in Afghanistan, compared to the eighty-five hundred U.S. troops and the hundred and eighty thousand Afghan troops on the ground there.

The attack also comes after a year of significant progress against the jihadi extremists who, like their brethren in Iraq and Syria, seek to establish a caliphate, with Jalalabad as their capital. In February, the top U.S. commander in Afghanistan, Army General John Nicholson, told a Congressional committee that ISIS-K had lost about a third of its fighters and two-thirds of its territory during the last year to drone strikes and Special Forces operations. More than a hundred additional fighters, including two leaders, have been killed this month, Afghan officials say.

In contrast, the war with the Taliban is at a stalemate, Nicholson said this year. He has called for the U.S. to deploy several thousand more troops in Afghanistan.

The decision to deploy the first MOAB also revealed the Trump Administration’s revised chain of command. With the approval of U.S. Central Command, Nicholson called in the strike, a reflection of how President Trump has shifted major wartime decisions to the U.S. military brass. Pressed on whether he had ordered the mission, Trump told reporters, on Thursday, “What I do is authorize my military.” President Obama, a lawyer, was deeply involved in decision-making on all major military actions. Trump has deflected decisions to the generals who hold key positions in his inner circle or who are in the field.

“Frankly,” Trump told a White House pool, “that is why they have been so successful lately. If you look at what has happened over the last eight weeks and compare that really to what has happened over the last eight years, you will see there has been a tremendous difference.”

Others disagreed. Former Afghan President Hamid Karzai criticized the mission. “This is not the war on terror, but the inhuman and most brutal misuse of our country as [a] testing ground for new and dangerous weapons,” he tweeted. The Taliban, which has also been at war with rival ISIS militants, also condemned the U.S. attack. “Using this massive bomb cannot be justified and will leave a material and psychological impact on our people,” it said in a statement Friday.

Success may also be short-term and relative in context of America’s longest war. Like the U.S. missile strike conducted this month against a Syrian military base, the military decision to use a super bomb in Afghanistan has only underscored the shallowness of U.S. political and diplomatic strategy. The United States has been at war in South Asia since 2001, at the cost of hundreds of billions of dollars. Since 2011, it has spent tens of millions in training, arming, and aiding Syrian rebels fighting the regime of President Bashar al-Assad. Yet in neither place has Washington figured out how to get beyond killing people—and having to use its biggest bombs.