How 9/11 Triggered Two Decades of Costly War for the U.S., Its Allies

“Our war on terror begins with Al Qaeda, but it does not end there … every nation in every region now has a decision to make: Either you are with us or you are with the terrorists.”

Those words, spoken by President George W. Bush in a televised address just nine days after the attacks on Sept. 11, 2001, were directed toward Congress and the American people, but they came to define a sprawling series of conflicts that have touched more than 120 countries across five continents in the years since.

The vision President Bush outlined that day — “Americans should not expect one battle, but a lengthy campaign unlike any we have ever seen” — has come true: The conflicts he coined the “war on terror” would go on to become some of the longest and costliest wars in U.S. history. And though 9/11 was an attack on the United States, the costs — human and otherwise — have been global.

Deaths of Innocents

In the two decades since the U.S. initiated its military retaliation to the 9/11 attacks, nearly 1 million people have died directly from its conflicts — and less than 2% of those were Americans or U.S. contractors, according to estimates compiled by the Costs of War Project at Brown University.

Civilians have suffered the most. In the five majority-Muslim countries that have been the primary battlefields of the post-911 conflicts, more than 377,000 civilians, journalists and nongovernmental organization workers have died as a direct result of the fighting — tens of thousands more than war fighters on either side, research shows.

Even those statistics reflect only a fraction of the harm and disruption the so-called “war on terror” have caused, says Stephanie Savell, co-director of the Costs of War Project.

“There have been 38 million people displaced by the post-9/11 wars. All of those people are now struggling for livelihood torn from their homes and communities.” Those people, as well, are predominantly not Americans, she says.

“Bush talked about extending American force to ‘all the dark corners of the world’ and if you look at the map where the U.S. is engaged in counterterror, it’s very heavily skewed toward countries with Black and brown populations,” Savell says.

Allied Involvement

The reach of post-9/11 wars extends well beyond the conflict zones. U.S. allies from across the globe have also contributed to, and suffered from, the loss of life.

Those contributions began with the initial efforts to track down Osama bin Laden in Afghanistan in 2001, and escalated further with the deployment of NATO’s International Security Assistance Force that year. By February 2011 — almost a decade after the first boots hit the ground — 47 countries had troops deployed in Afghanistan, and they constituted nearly a third of the total bootprint at the time.

In Iraq, support from U.S. allies was initially more limited. Only the United Kingdom, Poland and Australia contributed troops to the invasion at the war’s outset in 2003. But by the coalition’s peak in December 2005, allies had deployed more than 20,000 troops to the effort.

The global financial costs of the wars were also substantial. The five most financially generous U.S. allies in Afghanistan and Iraq spent an estimated $145 billion in military and non-military aid on those countries, according to one calculation. In both military and financial support, the United Kingdom was the biggest contributor to both war efforts.

Those estimates don’t include indirect costs associated with the war effort, costs that contribute to the estimated $8 trillion in U.S. spending on the post-9/11 wars.

Mission Drift

Though the U.S. has now withdrawn much of its military presence from Iraq and Afghanistan, the global “war on terror” continues.

“This war paradigm approach to the problem of terrorism is really misguided but not one the U.S. seems to be changing at all,” says Savell, of the Costs of War Project.

“It’s still training counterterror operations around the world, the CIA is still heavily involved in drone strike operations in countries and there are a lot of mechanisms of shadowy programs that allow them to continue operating.”

From 2018 to 2020 alone, the U.S. was involved in counterterrorism operations in 85 countries, according to her team’s research.

U.S. and allied countries argue that counterterrorism operations prevent larger, deadlier attacks against civilians and military forces. But even supporters of continued counterterror operations acknowledge that more people today are radicalized to violent extremism worldwide than in 2001.

“The best recruiting device for militant groups is drone strikes and state violence against often innocent people,” Savell says. “A military approach is the least effective way to deal with terrorist violence according to the research.”

This comes following research released in 2015 showing that more Americans have been killed in the U.S. by white supremacists, antigovernment extremists and other non-Muslim groups than by radical Muslims.

Even that doesn’t capture all the international involvement in U.S. or U.S.-assisted counterterrorism efforts. Some 54 countries reportedly participated in secret detention or “extraordinary rendition” programs where detainees of the U.S. are transferred to the custody of a foreign government for detention and interrogation, and sometimes torture, according to one Open Society Foundations report.

Those programs have shuttered, and the U.S. troops have mostly withdrawn, but that doesn’t mean the “war on terror” is over, Savell says.

“Just because U.S. troops are withdrawing from Afghanistan doesn’t mean the U.S. is changing its basic approach to dealing with terrorism.”

More from U.S. News

What Do Countries Teach About Terrorism

Using Empathetic Practices May Ease Polarization in a Post-9/11 World


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