On the 25th anniversary of September 11, we remember the nearly 3,000 people whose lives were taken that morning, the families who carried that loss forward, and the first responders and survivors whose lives were permanently changed. But the anniversary also requires looking at what the United States did in response- and what those decisions set in motion.
September 11 is first and foremost a day of mourning.
Nearly 3,000 people were killed when al-Qaeda terrorists hijacked four commercial airplanes and attacked the World Trade Center, the Pentagon, and United Airlines Flight 93 on September 11, 2001. Families lost parents, children, spouses, siblings, friends, and coworkers in a matter of hours. First responders entered burning buildings while others were running out. Survivors, firefighters, police officers, recovery workers, and residents of lower Manhattan continued to suffer health effects years after the attacks.
USCMO, the US Council of Muslim Organizations, joins Americans across the country in remembering those lives and condemning the attacks without qualification.
Al-Qaeda committed a deliberate act of mass murder. Its members claimed a religious justification for what they did, but the crime belonged to them. Muslim Americans did not carry out September 11, and an entire faith could never reasonably be assigned responsibility for the actions of a terrorist organization speaking in its name.
Muslims were among the Americans grieving that day.
What followed often erased that reality, blurring the line between confronting al-Qaeda and treating Muslims themselves as a security concern.
The United States unquestionably had to respond to the security failures exposed on September 11. Al-Qaeda had shown that a terrorist network operating overseas could take advantage of weaknesses in intelligence sharing, aviation security, and federal coordination and inflict catastrophic harm inside the United States.
The response did not remain confined to al-Qaeda or the failures exposed on September 11.
The War on Terror eventually encompassed military operations, surveillance programs, detention systems, intelligence partnerships, financial restrictions, immigration policy, and new theories of presidential war power. Afghanistan was only the beginning. U.S. counterterrorism operations and partnerships expanded into Iraq, Pakistan, Yemen, Somalia, Syria, Libya, the Sahel, and many other countries. Brown University’s Costs of War project found U.S. counterterrorism activity in 78 countries between 2021 and 2023, two decades after the attacks themselves.
Eventually presidents used the phrase “Global War on Terror” less often. Many of the institutions and powers created under it remained.
Twenty-five years later, the record is mixed. Some reforms made the country safer; other decisions produced consequences that continue long after the wars themselves.
America Became Better at Preventing Another 9/11
Before September 11, responsibility for counterterrorism was badly fragmented.
The 9/11 Commission later described agencies operating through bureaucratic “stovepipes.” Pieces of intelligence existed in different places without an effective system for connecting them. No single institution reliably coordinated the domestic and foreign sides of the threat.
The Department of Homeland Security was created. Congress established the Office of the Director of National Intelligence and the National Counterterrorism Center. Airport and aviation security changed dramatically. Intelligence sharing improved. Terrorist financing received far more attention. Agencies developed stronger systems for screening travelers, tracking networks, and passing threat information to one another.
The United States became substantially better at combining intelligence and following terrorist networks than it had been before September 11. Al-Qaeda’s senior leadership was gradually dismantled, and Osama bin Laden was killed in Pakistan in 2011. Years later, when ISIS captured large areas of Iraq and Syria and declared a territorial caliphate, the United States and its partners helped destroy that territorial project.
There has also been no foreign terrorist attack on U.S. soil approaching September 11 in scale or lethality.
There is no way to know how many attacks these reforms may have prevented. But the absence of another foreign attack approaching September 11 in scale cannot simply be dismissed when assessing the post-2001 security reforms.
The military record is far less straightforward.
An Emergency Authorization That Never Really Ended
Three days after September 11, Congress passed the 2001 Authorization for Use of Military Force. President George W. Bush signed it into law on September 18.
Its language gave the president authority to use “necessary and appropriate force” against those responsible for the attacks and those who had harbored them.
There was no expiration date.
There was also no list of countries in which the authority applied. Later administrations interpreted the authorization to cover additional organizations and conflicts under the concept of “associated forces,” even though that phrase does not appear in the original statute.
That interpretation allowed the authorization to survive far beyond the conflict Congress was contemplating in September 2001. Presidents from both parties continued using it in circumstances lawmakers could not have specifically anticipated when they voted in the immediate aftermath of the attacks.
The separate authorizations associated with the 1991 Gulf War and the 2003 Iraq War were finally repealed in 2025. The 2001 AUMF remains.
The 2001 AUMF also illustrates how emergency powers can become ordinary features of government. Congress enacted it in the immediate aftermath of an attack; a quarter-century later, the authorization remains in force.
A person born the week Congress passed the AUMF is now 25 years old.
Afghanistan: From Self-Defense to a Twenty-Year Occupation
Of all the military interventions that followed September 11, Afghanistan had the clearest connection to the attack itself.
Al-Qaeda operated from Afghan territory under the protection of the Taliban government. U.S. forces entered Afghanistan in October 2001, and the Taliban government fell rapidly. Al-Qaeda lost the sanctuary from which it had planned the attacks.
But the American mission did not end with removing the Taliban government and disrupting al-Qaeda’s sanctuary.
The United States remained in Afghanistan for almost twenty years. What began as a campaign against al-Qaeda expanded into counterinsurgency, military occupation, training and equipping Afghan security forces, constructing government institutions, supporting elections, funding development, and attempting to create a political system that could survive without permanent American backing.
None of those nation-building goals appeared in the original authorization for war.
There were meaningful improvements during those years. Millions of Afghan children attended school. Women and girls gained opportunities that the Taliban had denied them. Health services, infrastructure, media, and public institutions expanded in important ways.
The same twenty years also brought enormous costs: civilian casualties, displacement, corruption, dependence on foreign funding, and an Afghan government increasingly unable to survive without outside troops, contractors, money, and logistical support.
By the end, the basic purpose of the intervention was far less clear than it had been in October 2001.
American forces repeatedly defeated the Taliban on the battlefield without resolving the much harder question of what political system could endure after they left.
When U.S. military and contractor support disappeared in 2021, the Afghan government collapsed at extraordinary speed. The Taliban returned to Kabul twenty years after having been removed from power.
The collapse does not erase the real improvements Afghans experienced during those years. It does, however, expose how far the mission had drifted from destroying al-Qaeda’s sanctuary toward trying to construct an Afghan political order that could outlast the American presence.
By then, destroying al-Qaeda’s sanctuary was no longer an adequate description of the mission, and Washington never settled on a convincing definition of what success would ultimately look like.
Iraq: When the War on Terror Became Regime Change
Iraq was different from Afghanistan in one fundamental respect: Saddam Hussein’s government had not carried out September 11.
The invasion of Iraq in 2003 therefore required a separate congressional authorization and a different public case for war.
The Bush administration focused heavily on Saddam Hussein’s alleged weapons programs, the possibility that Iraq could threaten the United States or its allies, and the broader danger posed by the Iraqi government.
The official British Iraq Inquiry later concluded that Saddam Hussein did not pose an urgent threat in March 2003, that intelligence concerning weapons of mass destruction had been presented with unjustified certainty, that peaceful alternatives had not been exhausted, and that planning for the aftermath of invasion was seriously inadequate.
Saddam Hussein headed a brutal dictatorship. His government was responsible for repression, war, executions, torture, and atrocities against Iraqis.
Saddam’s brutality was real, but it was a separate question from whether invading Iraq was necessary to defend the United States from terrorism.
By 2003, the War on Terror was no longer limited to breaking up the organization responsible for September 11. U.S. policy had expanded toward regime change and the belief that military power could transform the political order of the Middle East.
American forces removed Saddam Hussein’s government within weeks. Building a stable order after its collapse proved vastly more difficult.
State institutions were dismantled faster than a stable replacement could emerge. Iraq became a battlefield involving insurgents, sectarian militias, foreign powers, jihadist movements, and competing political factions. Violence devastated Iraqi society for years.
Al-Qaeda in Iraq grew during the occupation. Its successors eventually became part of the organizational lineage that produced ISIS.
ISIS cannot be explained by the American invasion alone. The Syrian civil war, Iraqi sectarian politics, extremist ideology, regional rivalries, and decisions made by Iraqi leaders all mattered. But the invasion and subsequent breakdown of Iraqi institutions were part of the conditions from which the organization emerged.
The breakdown of Iraqi institutions and the instability of the occupation created conditions that jihadist organizations were able to exploit. A war promoted in part through the language of combating terrorism helped produce a political environment in which a new and extraordinarily violent terrorist movement later flourished.
By 2014, the United States was again conducting a major military campaign in Iraq, this time against ISIS.
Research on terrorist organizations also complicates the assumption that military intervention is usually the most effective tool. In a study of 648 terrorist organizations active between 1968 and 2006, Seth Jones and Martin Libicki found that among groups that ended, roughly 43 percent moved into political processes and 40 percent were primarily defeated through policing or intelligence. About 7 percent ended mainly through military force.
Military force still has a role, especially against armed groups controlling territory. The research nevertheless cautions against treating terrorist networks, insurgencies, dictatorships, and failed states as versions of the same problem requiring the same solution.
Iraq became one of the clearest examples of what can happen when those distinctions collapse.
The Human Cost
For people living in the countries where these wars unfolded, debates over presidential authority and counterterrorism doctrine translated into casualties, displacement, destroyed infrastructure, and disrupted lives.
Brown University’s Costs of War project estimates that approximately 905,000 to 940,000 people died directly from violence in major post-9/11 war zones through 2023. Between 408,749 and 432,093 were civilians.
Brown also estimates another 3.6 million to 3.8 million indirect deaths associated with war-related destruction of health systems, food supplies, economies, water infrastructure, and other basic conditions necessary for survival.
Its combined estimate reaches roughly 4.5 million to 4.7 million direct and indirect deaths.
The larger number needs context. Brown is not claiming to possess a list of 4.7 million individually documented deaths. Indirect mortality is modeled, and the researchers themselves acknowledge uncertainty.
The figure also should not be interpreted as 4.5 to 4.7 million people killed directly by U.S. forces. These were complicated wars involving many armed actors. American and coalition forces, governments, insurgents, militias, al-Qaeda, ISIS, and other organizations all caused deaths.
Brown’s estimate concerns the wars as a whole, not deaths attributable to a single actor. Even with that qualification, the scale is extraordinary.
Its country estimates include roughly 176,000 direct war deaths in Afghanistan through August 2021, around 67,000 in Pakistan, more than 275,000 in Iraq in earlier comparative accounting, and approximately 112,000 in Yemen through 2021.
War does not become less consequential because responsibility is divided among several actors.
More Than 38 Million People Displaced
The damage cannot be understood through death counts alone.
Brown estimates that more than 38 million people were displaced at some point across Afghanistan, Iraq, Pakistan, Syria, Yemen, Somalia, Libya, and the Philippines in conflicts included within its post-9/11 framework.
Because the number is cumulative, it should not be read as 38 million people currently displaced or as displacement attributable exclusively to U.S. forces. It instead conveys the extraordinary geographic reach of the wars included in Brown’s accounting.
Afghans fled into Pakistan and Iran. Iraqis sought safety across the region. Syrians produced one of the largest refugee crises of the modern era. Communities were broken apart, families rebuilt their lives abroad, and neighboring countries absorbed enormous humanitarian pressures.
Those consequences eventually reached far beyond the war zones themselves. Refugee movements reshaped politics in Europe and elsewhere. Border policy hardened. Migration became a defining political issue.
Wars launched under a national-security framework in Washington altered the lives of people who had never posed a threat to the United States.
What the War on Terror Meant at Home
Muslim Americans experienced the post-9/11 era both through what happened overseas and through the transformation of life at home.
They watched wars spread through predominantly Muslim countries while facing a changed political atmosphere in the United States.
FBI records show the scale of the immediate backlash. There were 28 reported anti-Islamic hate-crime incidents in 2000. In 2001, there were 481.
Those FBI figures capture only part of the backlash.
Arabs, Sikhs, South Asians, and others were assaulted because attackers perceived them to be Muslim or Middle Eastern. Human Rights Watch documented violence against communities that perpetrators often lumped together under the same imagined identity.
The PATRIOT Act itself condemned discrimination against Arab, Muslim, and South Asian Americans. That language appeared in the same legislation that greatly expanded the federal government’s security authorities.
Public officials insisted that the United States was not at war with Islam. In everyday life, however, Muslims were repeatedly asked to explain themselves in relation to terrorism. Mosques and charities faced new scrutiny. Immigration rules tightened. Watchlists expanded. Federal investigations and surveillance became recurring concerns within Muslim institutions.
An entire generation grew up hearing versions of the same demand: prove that you belong, prove that you reject terrorism, prove that your religion is compatible with American life.
The premise was backwards.
The terrorists were responsible for September 11. American Muslims were not.
Muslim Americans did not owe the country collective repentance for a crime committed by al-Qaeda.
Surveillance and the Expansion of Government Power
The domestic response to September 11 also gave federal agencies surveillance powers that would remain controversial for decades.
The PATRIOT Act expanded authorities involving terrorism investigations, records, intelligence sharing, financial investigations, surveillance, and delayed-notice searches. Some provisions were temporary. Others survived or were later amended.
One of the most controversial programs involved bulk collection of Americans’ telephone metadata under Section 215.
The program remained largely outside public view until Edward Snowden’s disclosures in 2013.
The bipartisan Privacy and Civil Liberties Oversight Board later concluded that the bulk program lacked a viable legal foundation and found little evidence that its unique capabilities had produced counterterrorism results that could not have been obtained through other methods.
Congress changed the system through the USA FREEDOM Act of 2015.
The Section 215 fight also shows that the post-9/11 security architecture was not immune from challenge. Courts, lawmakers, journalists, whistleblowers, inspectors general, and civil-liberties organizations challenged parts of it and sometimes succeeded.
FISA Section 702, created in 2008, authorizes surveillance targeting non-U.S. persons reasonably believed to be outside the country. Americans’ communications can nevertheless be collected incidentally and later queried. Its statutory authorization lapsed in June 2026, though existing certifications allowed substantial collection to continue temporarily while Congress debated what should happen next.
The current Section 702 debate is therefore not separate from the post-9/11 era; it is one of its surviving political and legal disputes.
Guantánamo and an Exceptional Legal System
Guantánamo Bay became one of the most enduring symbols of the War on Terror.
The Bush administration sought to hold foreign terrorism detainees there outside the ordinary federal criminal system and with highly restricted judicial review.
The Supreme Court eventually imposed limits on that system. In Hamdan v. Rumsfeld, the Court rejected the administration’s original military commission structure. In Boumediene v. Bush, it held that detainees at Guantánamo possessed constitutional habeas rights and could challenge their detention in federal court.
Those rulings constrained the detention system but did not close Guantánamo.
After 11 Yemeni detainees were transferred to Oman in January 2025, its population fell to 15 men.
That is a fraction of the population held there in the early years.
Nearly twenty-five years after the prison opened, many of the legal questions it created remain unresolved.
Torture and the Damage Done in the Name of Security
The CIA’s detention and interrogation program produced another lasting controversy.
The Senate Intelligence Committee majority concluded, after examining millions of pages of CIA records, that the agency’s “enhanced interrogation techniques” were more brutal than officials had publicly represented. It also concluded that CIA claims about their effectiveness were inaccurate and that oversight bodies had received misleading information.
The record documented waterboarding, prolonged sleep deprivation, isolation, and other coercive practices.
CIA officials and Republican members of the committee disputed important parts of the majority’s conclusions, particularly the argument that coercive interrogation did not produce uniquely valuable intelligence.
Whatever the dispute over intelligence value, the program carried substantial legal and diplomatic consequences for the United States.
The Senate committee concluded that the program harmed America’s standing abroad.
The damage to U.S. credibility is difficult to quantify. The contradiction itself was clear: Washington was defending the rule of law against organizations that rejected it while authorizing practices that placed its own commitment to those principles under question.
An $8 Trillion Era
The War on Terror also produced financial obligations that extend decades beyond the fighting.
Brown researchers estimated approximately $8.043 trillion in post-9/11 costs and obligations in their 2021 accounting.
The $8 trillion estimate includes considerably more than battlefield expenditures.
It includes about $2.1 trillion in Defense Department war operations, more than $1 trillion in interest associated with war borrowing, roughly $1.1 trillion in homeland-security expenditures, increases to the Pentagon’s base budget, and medical and disability obligations for veterans.
Around $2.2 trillion of the total represents projected veterans’ medical and disability costs through 2050. Brown’s full budgetary analysis is available here.
A war can end for the public long before it ends financially.
Veterans and their families also continue living with the physical and psychological consequences long after deployments stop appearing in the news.
Americans Look Back Differently Now
The political consensus that existed in the months after September 11 has largely disappeared.
In October of that year, roughly 88 percent of Americans supported military action in Afghanistan.
By 2023, 63 percent of Republicans and 65 percent of Democrats said the Afghanistan war had not been worth fighting. Another poll found 61 percent of Americans believed the Iraq invasion had been the wrong decision.
The threat Americans worry about has changed as well.
An August 2026 Reuters/Ipsos survey found 61 percent considered ideologically motivated domestic extremists a greater danger than attackers coming from abroad. Another 65 percent opposed warrantless domestic surveillance.
Public confidence in Washington’s ability to prevent terrorism has also fallen. An anniversary survey put it at roughly 55 percent, compared with 88 percent shortly after September 11.
Americans are therefore living with a strange post-9/11 legacy: a counterterrorism system vastly more capable than the one that existed in 2001, accompanied by considerably greater skepticism toward expansive national-security claims.
So What Did the War on Terror Accomplish?
The answer depends heavily on which part of the post-9/11 response is being judged.
The parts closest to conventional counterterrorism produced some of the strongest results. Intelligence agencies coordinated more effectively, aviation security improved, terrorist financing became more difficult, and governments developed better systems for detecting and tracking networks.
Those successes are much harder to find in the record of prolonged military intervention.
Afghanistan began with a clear objective connected directly to al-Qaeda and became a twenty-year political project whose institutions collapsed after American withdrawal.
Iraq went further. It turned the logic of the War on Terror toward regime change in a state that had not carried out September 11, destabilizing a country whose subsequent turmoil became fertile ground for insurgency and jihadist movements.
Global terrorism deaths fell 28 percent in 2025, reaching their lowest level in a decade, but severe violence remained concentrated in parts of Africa. Nigeria recorded 750 terrorism deaths, while the Democratic Republic of Congo recorded 467. Armed jihadist groups remain active across the Sahel and elsewhere.
The United States therefore faces a very different threat landscape from the one it confronted in 2001.
Terrorism remains a serious security problem. But twenty-five years of experience provide strong reason to question the assumption that large-scale military intervention is an effective default response to it.
Twenty-Five Years Later
Any accounting of the last twenty-five years should begin with the nearly 3,000 people killed on September 11.
Their families have now carried that absence for a quarter of a century. Nothing in the debate over American foreign policy should diminish what happened to them or soften responsibility for the terrorists who murdered them.
The demand for protection after September 11 was understandable. But fear and urgency did not make the policies adopted afterward inevitable. Afghanistan became a twenty-year occupation. Iraq became a regime-change war despite having no responsibility for September 11. Emergency powers written in 2001 survived presidents, wars, elections, and the death of Osama bin Laden.
Hundreds of thousands died directly in the wars included in Brown University’s post-9/11 accounting. Millions more are estimated to have died from the wider destruction those conflicts produced. Tens of millions were displaced. Iraq’s institutions were shattered, Afghanistan’s externally supported political order collapsed, and new extremist movements grew inside some of the instability left behind.
Most of the societies living through those consequences were Muslim.
At home, American Muslims experienced another legacy. Anti-Muslim hate surged after September 11. Surveillance, watchlists, investigations, and political suspicion became familiar parts of community life. People who had nothing to do with al-Qaeda were repeatedly asked to answer for its crimes simply because they shared a religion that the attackers had invoked.
This is one of the most painful contradictions of the post-9/11 period. The terrorists who carried out the attacks claimed Islam as their justification, but their crime was never the responsibility of Muslim Americans. Muslims did not owe the country an apology for September 11. They mourned alongside everyone else. They lost coworkers, neighbors, friends, and fellow citizens. Yet for years afterward, an entire faith community was often treated as though it stood adjacent to the crime rather than among the Americans grieving it.
Twenty-five years later, New York itself offers a striking reminder of how much has changed. The city that suffered the greatest loss on September 11 is now led by its first Muslim mayor, Zohran Mamdani. A Muslim New Yorker is not standing outside the city’s remembrance or being asked to explain whether he belongs there. He is helping lead a city whose history, grief, and future are also his own.
There is something deeply meaningful in that. It does not erase Islamophobia, and it certainly does not erase the policies or prejudices that Muslim communities endured after 9/11. But it exposes the false premise that Muslims were somehow outsiders to the American experience of that day. They never were. Muslim Americans were part of the country before September 11, lived through the attack with the country, endured much of the backlash that followed, and spent the next twenty-five years building institutions, serving their communities, running for office, and refusing to let terrorism define their place in American life.
America entered the War on Terror with unmatched military and economic power. That power succeeded at disrupting genuine threats and destroying terrorist infrastructure. But Washington also repeatedly treated its ability to overthrow governments as evidence that it could control the political order that followed.
The wars in Iraq and Afghanistan gave little reason for such confidence.
Military force proved effective at removing governments, killing commanders, destroying camps, and seizing territory. It was far less effective at building legitimate political systems, resolving internal conflicts, or preventing new movements from emerging from the disorder that followed.
The victims of September 11 deserve to be remembered as people, not turned into permanent justification for every war or emergency authority that followed their deaths. The people of Afghanistan, Iraq, Yemen, Pakistan, Somalia, Syria, and other countries also deserve to be seen as human beings rather than distant costs on an American security ledger.
Remembering one group of victims does not require ignoring the other.
Mourning September 11 fully should not prevent an examination of what the United States did in its aftermath. A quarter-century later, that examination is part of understanding the attack’s legacy.
That means asking whether intervention actually made people safer, whether wars accomplished what they were supposed to accomplish, whether the destruction left behind was considered seriously enough before decisions were made, and whether a country can defend itself without turning entire populations into collateral consequences of its security policy.
The next twenty-five years of American foreign policy should be shaped by those answers.
