The US launched the Global War on Terror after 9/11

The US and allies invaded Iraq based on flawed intelligence about potential weapons of mass destruction.

9/11 reshaped US foreign and military policy for decades, shifting focus to non-state actors and the Middle East.

The War on Terror used controversial tactics like torture and secret prisons

As part of its post-9/11 strategy, the US employed enhanced interrogation, extraordinary rendition, and secret CIA black sites—practices widely criticized as torture and violations of international law and human rights.

How NATO responded to 9/11

The collective defense clause of the NATO constitution has only been invoked one time: after the 9/11 terrorist attacks against the United States. This video explores the immediate actions NATO took to respond to the attacks to support the United States. These firsthand clips from 2001 give a sense of the magnitude of the moment and the difficult decisions facing NATO leaders at the time.

Osama bin Laden declared jihad—a call for armed struggle framed as a religious duty—against the US in 1996.

The 2001 Authorization for Use of Military Force has been used by five administrations to justify military operations in at least 22 countries.

The PATRIOT Act expanded government surveillance after 9/11

Signed into law weeks after the attacks, the PATRIOT Act granted federal agencies sweeping powers to monitor communications, access records, and conduct surveillance—sparking ongoing debates over privacy, civil liberties, and national security.

The Taliban provided al-Qaida with a safe haven in Afghanistan before 9/11 and returned to power in 2021

A fundamentalist Islamist movement, the Taliban ruled most of Afghanistan before 9/11, providing al-Qaida with training grounds and sanctuary. After 20 years of war, it regained power following the U.S. withdrawal in 2021.

9/11 permanently changed air travel security in the US with the creation of the Transportation Security Administration.

NATO's Article 5 has been invoked once—after 9/11

The article was invoked the day after the attacks and launched a series of NATO campaigns to fight global terrorism. This page includes excerpts from a speech by then-NATO Secretary General Jens Stoltenberg about the attacks and the organization’s response.

President Bush addressed the nation on 9/11 from the Oval Office, watched by an estimated 80 million people.

Experience 9/11, the deadliest terrorist attack on American soil, as it happened.

9/11 was the first global disaster watched in real time across the world

As the first plane struck at 8:46 a.m. ET, CNN's live feed broadcast images worldwide within minutes. An estimated 2 billion people watched the collapse of the Twin Towers live.

Decades of instability in the Middle East gave rise to al-Qaida.

Infographics explaining global terrorism trends

Our World in Data’s terrorism page details global trends in terrorism. Through interactive infographics, the site shows how the number of terrorist acts varies around the world and how it has changed over time. Sections investigate common definitions of terrorism, trends in global terrorism deaths, and the global distribution of terrorism. Additional segments highlight airline hijackings, public opinion, and media coverage of terrorism. Explore this website for an array of infographics on terrorism.

The US war on drugs, explained

The United States has been fighting a global war on drugs for decades. By making drugs more expensive and less available, the US has sought to reduce drug use and inhibit the international drug trade. However, increasing prison populations,...

US intelligence warned in multiple reports of al-Qaida's plans to strike before 9/11.

Vladimir Putin was the first world leader to call Bush after 9/11, and visited the US two months later.

NATO has only invoked its mutual defense clause once, in the days after the 9/11 attacks.

al-Qaida targeted multiple US interests in attacks before 9/11

Before 9/11, al-Qaeda carried out several deadly attacks on US targets—including the 1998 embassy bombings in Kenya and Tanzania and the 2000 bombing of the USS Cole—killing hundreds of people.

Americans showed an unprecedented surge of patriotism after 9/11

In the weeks following 9/11, 79% of US adults reported displaying the American flag, and a year later, 62% said they "often felt patriotic" due to the attacks.

A formal declaration of war automatically triggers hundreds of statutes granting the president sweeping domestic authority

Beyond authorizing military force abroad, a formal declaration activates a wide range of domestic powers, including authority over enemy property, trade restrictions, and emergency economic authority. It also waives the 60-day time limits under the War Powers Resolution.

The Soviet-Afghan War empowered militant jihadist networks

US and Pakistani support for Afghan mujahideen in the 1980s inadvertently built the infrastructure—training camps, ideology, and global fighters—that later evolved into al-Qaeda's foundation.

The US never formally declared war in Vietnam

Instead of formally declaring war, Congress passed the Gulf of Tonkin Resolution in 1964, granting President Johnson broad authority to use military force. The resolution became the legal basis for escalating US involvement without an official declaration of war.

Hitler declared war on the United States four days after Pearl Harbor

Despite having no treaty obligation to join Japan’s fight, Hitler declared war on the US on Dec. 11, 1941. The move pulled America into the European theater and is widely seen as one of Hitler’s most strategic blunders.

President George W. Bush learned of the 9/11 attacks while visiting a classroom.

Coverage of the 9/11 terrorist attacks helped shape Wikipedia's editorial policies

Launched nine months earlier, the site was featured on Yahoo's news page, attracting traffic from information seekers as dozens of new editors created hundreds of articles, including memorials, conspiracy theories, and donation and volunteer pages. Discussions between editors would begin establishing rules for handling breaking news events.

Congress has formally declared war 11 times across five conflicts, the last in 1942

The five declared wars were the War of 1812, the Mexican-American War, the Spanish-American War, World War I, and World War II. Every major American military conflict since Korea, Vietnam, Iraq, and Afghanistan has been fought without a formal declaration.

One Day in America series reveals the full timeline and human toll of 9/11

This National Geographic episode reconstructs the events of 9/11—highlighting the Pentagon attack, Flight 93 hijacking, South Tower collapse, and rescue efforts—offering a detailed, chronological account of how the day unfolded.

The attacks prompted a quick jump in American public support for war

In a Gallup poll taken days after the attack, an extraordinary 97% of Americans approved Congress declaring war on Japan—reflecting overwhelming national unity in the wake of the strike.

The treaty's Article 5 requires mutual defense, but not necessarily military action.

al-Qaida was founded in 1988 by Osama bin Laden

The group emerged in 1988 from the militant networks formed during the Soviet-Afghan War. Under Osama bin Laden's leadership, it combined jihadist ideology with global ambitions—eventually orchestrating attacks across Africa, the Middle East, Europe, and the United States.

The Iraq War, in photos

2023 marked the 20th anniversary of the start of the Iraq War. The U.S. carried out its first airstrikes in Iraq on March 20, 2003 – during a phase of ‘shock and awe’. Fires burning in and around Baghdad; U.S. soldiers on patrol; Iraqi...

A trade war is an economic conflict where nations impose tariffs or other trade barriers on each other in retaliation for similar actions.

Why the First Gulf War occurred—and how it played out

This video navigates the conflict’s core—from Iraq's August 2, 1990 invasion of Kuwait through Operation Desert Shield’s buildup, to the decisive air and ground assault of January–February 1991. It spotlights coalition tactics and rapid liberation of Kuwait, highlighting how precision bombing and advanced tech reshaped modern warfare.

World War I brought attention to US reliance on mineral imports

Domestic stockpiles were inadequate for the extended trade disruptions caused by the four-year war. In response, the US Geological Survey increased its geological mapping to help search for important metals alongside new oil fields for fuel.

President Bush threw the first pitch at the World Series in New York City less than two months after 9/11.

After the 9/11 terrorist attacks, US radio stations created a list of 150 banned songs they feared would be insensitive.

George W. Bush delivered the first State of the Union livestreamed online

In 2002, George W. Bush became the first president to livestream the State of the Union, using the address to label Iraq, Iran, and North Korea an "axis of evil," shaping US strategy during the War on Terror.

How the US entered WWI in 1917

Originally taking a position of neutrality during the course of World War I, the United States of America eventually relented. Entering the war in 1917, support for the British and French had risen and Americans were incensed by Germany's overtures to Mexico and U-boat attacks that sank ships and ended American lives. See how and why the US entered WWI in this article.

After the 9/11 terrorist attacks, The Onion stuck with satire, defying what some were predicting was 'the death of irony.'

World War I causes

World War I was, as the name says, truly war on the global scale. Fought between the French, Russian, British, Austria-Hungary, Ottoman, and Russian Empires, it was in part, a battle for territory. And after the war ended, several of these empires collapsed. Explore the different causes of World War II in this article.

The second attack used to justify full-scale US involvement in Vietnam never happened as reported

In August 1964, Washington claimed that North Vietnam launched two attacks on US destroyers in the Gulf of Tonkin. The second, used to justify escalating the US war effort, was later revealed to most likely have been a radar mistake.

Japan's imperial expansion in Asia in the 1930s set the stage for war with the US.

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One hijacked plane struck the Pentagon on 9/11, killing 125 people inside

American Airlines Flight 77 crashed into the Pentagon's west side, destroying a section of the building and killing all 59 on board, along with 125 military and civilian personnel, making it the deadliest attack on the US military headquarters.

Watch Jon Stewart's unifying opening monologue during his first show back after the 9/11 terrorist attacks.

The world rapidly decolonized after World War II, with roughly a hundred new countries emerging between 1945 and 1989.

Decolonization isn't complete, as nearly 2 million people were living in UN-designated non-self-governing territories as of 2023.

Since World War II, formal declarations of war and peace treaties have become increasingly rare, replaced by cease-fires, authorizations of force, and "special military operations."

The 1967 war was the first use of oil as a geopolitical weapon

Following the June 1967 Arab–Israeli war, Saudi Arabia, Kuwait, Iraq, Libya, and Algeria embargoed oil shipments to the US, UK, and West Germany. While the move did not have a large impact, it reshaped global oil flows, and foreshadowed OAPEC's later actions.

Free speech has often been restricted in wartime, potentially unconstitutionally

From the Sedition Act of 1798 to the prosecution of anti-war activists during World War I, the US government repeatedly curtailed speech and dissent during wartime—actions widely criticized and, in some cases, later deemed unconstitutional.