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

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

In the wake of 9/11, the US declared a Global War on Terror—initiating military operations in Afghanistan and Iraq, expanding surveillance, and forming international coalitions to combat terrorism and disrupt extremist networks worldwide.

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

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

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

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.

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

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.

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

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.

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

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.

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.

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

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.

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.

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

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.

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.

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.

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.

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

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

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

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

Explore the Council on Foreign Relations' essay collection on the future of US foreign policy

This project brings together expert essays examining the future of American strategy, regional relations, geoeconomics, great power rivalry, and war in a rapidly changing global landscape.

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.

AP Photos: 20 images documenting the enormity of 9/11

The Associated Press shares 20 photographers’ frames from Sept. 11, 2001, when hijackers crashed commercial planes into New York’s World Trade Center, the Pentagon and a Pennsylvania field.

Israel’s swift victory in the Six-Day War redrew the map of the Middle East

Learn more about the June 1967 conflict which shifted territorial lines across Israel and its neighbors—Egypt, Jordan, Syria, and Iraq—reshaping the Middle East’s political landscape with long-lasting geopolitical ramifications.

View artifacts at the Smithsonian that tell the story of 9/11.

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 Truman Doctrine marked the start of US containment strategy

Introduced in 1947, the Truman Doctrine pledged US support for nations resisting communism—starting with Greece and Turkey—and launched the containment policy that defined early Cold War strategy.

The threat of nuclear annihilation reshaped global diplomacy

The first use of atomic weapons introduced the possibility of a war with no survivors. This article examines how nuclear fear shaped Cold War diplomacy and continues to influence international relations today.

The National Security Council advises the president on foreign policy and national defense

Created in 1947, the NSC coordinates military, diplomatic, and intelligence policy matters. Chaired by the president, it includes key Cabinet officials and senior advisers who shape American responses to global crises and security threats.

After the 9/11 terrorist attacks in New York City’s Financial District in 2001, many banks decided to relocate

Much has been said about why today’s top banks are typically no longer headquartered on Wall Street itself. The terrorist attacks in New York City’s Financial District on Sept. 11, 2001, are one reason many banks decided to relocate.

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.

Hear how the US and Iran went from close allies to bitter adversaries after the 1979 revolution.

The War Powers Act may have ironically given presidents more discretion to engage in hostilities, not less

In this wide-ranging podcast on Congress's power to declare war, scholar Gary Schmitt argues that the War Powers Act, ironically, gave presidents a legal framework for initiating hostilities, creating a 60-day window for unilateral action that hadn't existed before.

Before World War II, the US was a Pacific power

Decades before Pearl Harbor, the US held major Pacific territories—Hawaii, the Philippines, Guam, American Samoa, and numerous island bases—giving it strategic reach across the western Pacific. This presence increasingly overlapped with Japan’s imperial ambitions in the region, contributing to rising tensions.

9/11 first responders still deal with significant mental and physical impairments.

The Roosevelt Corollary transformed the Monroe Doctrine from a defensive warning into a rationale for US military intervention

In 1904, President Theodore Roosevelt declared that the US had the right to exercise international police power in Latin America. Over the following two decades, the US intervened militarily in the region about a dozen times—often enough that Marines became known locally as "State Department troops."

The power and influence of the American presidency have expanded significantly over time—far beyond what the founders envisioned.

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...

The world is shifting from unipolarity toward a multipolar order

The post-Cold War world was briefly unipolar after 1991, with the US standing alone as a global superpower following decades of US-Soviet bipolarity. Analysts increasingly describe today's order as multipolar, with China, Russia, the US, and regional powers all competing for influence.

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

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.

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 Arab Spring engulfed the Middle East – and changed the world

The Arab Spring engulfed the Middle East, unleashing consequences that still shape the world today. In 2011, the Arab Spring began with protests in a small Tunisian city. Those protests led to an era of uprisings and civil war in the Arab world,...

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.

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.