By Hanna Duggal and Alia Chughtai11 Sep 2026

Twenty-five years have passed since 19 al-Qaeda hijackers seized four commercial aeroplanes and slammed into the World Trade Center and the Pentagon, killing nearly 3,000 people.

What followed was a series of US-led wars that reshaped Washington’s foreign policy for a generation, in which every year since 2001, US forces have bombed a country somewhere in the world, devastating the lives of millions.

“Everything changed,” Omar*, an Iraqi student at the time of the 2003 invasion of Iraq, told Al Jazeera, recalling how the war was fought on the false pretence that the country harboured weapons of mass destruction.

Less than a month after 9/11, the US invaded Afghanistan, launching what President George W Bush called the “War on Terror” – a series of seemingly endless wars and military campaigns spanning Afghanistan, Iraq and countries across the Middle East, South Asia and Africa.

According to the Cost of War project at Brown University’s Watson Institute for International and Public Affairs estimates that US-led wars since 2001 have directly or indirectly killed an estimated 4.5 to 4.7 million people – including approximately 940,000 direct deaths and 3.6 to 3.8 million indirect deaths from disease, malnutrition and health complications.

Afghanistan: 176,000 direct war deaths

On October 7, 2001, the US launched Operation Enduring Freedom. The Taliban fell within weeks, but the war went on to span nearly 20 years across four US presidents – the longest conflict in US history.

An estimated 176,000 people died as a direct result of the war, according to an analysis from the Costs of War project, while hunger, disease and untreated injuries killed hundreds of thousands more.

Food insecurity rose from 62 percent of Afghans before the war to 92 percent after it, and unexploded ordnance and landmines continue to kill and maim civilians.

In 2021, the Taliban regained control of Afghanistan.

Iraq: 315,000 direct war deaths

Less than two years later, on March 19, 2003, the US launched its invasion of Iraq.

Omar was 18 years old when the Iraq war began. “We remember the sounds [of the bombs]; we were very afraid,” he told Al Jazeera.

Omar recalls how some of his friends went to see what was happening as the war reached Baghdad, despite warnings that it was too dangerous. “I told them, why are you going?” he says. “Then they went, and they didn’t come back. It’s very sad when we remember.”

Alongside the ground wars, the US conducted largely undeclared air and drone campaigns in Pakistan, Yemen, Somalia, Afghanistan and against ISIL in Iraq and Syria.

Since 2004, the Bureau of Investigative Journalism has recorded:

• 423 US strikes in Pakistan, killing an estimated 2,499–4,001 people, including 424–966 civilians
• In Yemen, it recorded at least 186 strikes and raids, killing at least 853 people, including 158 civilians
• In Somalia, 19–23 strikes between 2001 and 2016 killed 188–276 people

In 2011, during a crackdown on protests in Libya under Muammar Gaddafi, US and NATO led an air campaign under a UN mandate to protect civilians. Over seven months, there were nearly 9,700 strikes launched on the country before Gaddafi was captured and killed by rebel fighters, according to Amnesty International.

In 2014, the US-led campaign against ISIL in Iraq and Syria, known as Operation Inherent Resolve, involved a strong air and ground campaign involving tens of thousands of bombs.

By 2018, the destruction and loss of life was significant, while officials acknowledged 1,417 civilian deaths, Airwars, a London-based nonprofit that tracks civilian harm from military operations, estimates the true toll at between 8,264 – 13,360.

The Costs of War estimates that more than 38 million people across Afghanistan, Iraq, Pakistan, Yemen, Somalia, the Philippines, Libya and Syria have been displaced by the post-9/11 wars, either abroad or within their own countries.

More than two decades on, people are still being forced from their homes.

Last year, Iran and Pakistan pushed roughly 2.9 million Afghans back across the border. In Iraq, more than a million people remain displaced two decades after the invasion.

Ayesha*, a 40-year-old Afghan mother, has spent much of her life moving between Afghanistan and Iran after repeated displacement. Her family first fled Afghanistan in 1994, returned in 2000, and fled again in 2002 after the US invasion. After living in Iran for 11 years, she and her children were expelled and forced to return to Afghanistan.

“I went and came back many times. This last time, we were there for 11 years – but then the Iranians kicked us out and expelled my children from school,” Ayesha said.

More than 800,000 US troops served in Afghanistan, where approximately 2,500 were killed and 20,000 wounded before the last US forces withdrew in 2021. Across the US, UK, and allied forces, nearly 3,500 coalition personnel were killed and more than 23,500 injured.

According to the Defense Casualty Analysis System, 3,481 US military personnel died in the Iraq War, and more than 31,000 were wounded.

The long-term costs have also been enormous. The Costs of War Project estimates that caring for post-9/11 veterans in the United States could cost $2.2 trillion to $2.5 trillion by 2050, much of it still unpaid. Many veterans continue to face a mental-health crisis.

“Four times as many US service members and veterans died by suicide as were killed in combat during the post-9/11 wars,” Stephanie Savell, director of the Costs of War Project, told Al Jazeera

”There are people returning with higher rates of PTSD and traumatic injuries who are then redeployed more often than in historical times. So you’re really seeing … the costs of war, even among veterans and service members, borne within particular segments of the population rather than the population as a whole.”

The United States has spent an estimated $5.8 trillion on two decades of war, with an additional $2.2 trillion reserved for veterans’ care in the coming decades – bringing the total cost to at least $8 trillion.

By 2030, the US will have spent as much on interest as on the fighting itself, a debt today’s under-25s will help pay off.

Polls show Americans have little appetite for wars of aggression abroad, and the current war in Iran is deeply unpopular with the public.

Savell says that some who voted for Trump did so partly because he promised to end “forever wars” and talked about peace, but “that certainly has been the opposite of the case since he’s taken office,” with air strikes intensifying in Somalia and Yemen, rules of engagement loosened, and protections for civilians rolled back.

“Not to mention launching this war in Iran, the boat strikes in the Caribbean … just kind of across the board, he’s intensifying US violence.”

*Some names have been changed for anonymity.