9/11 reshaped US foreign and military policy for decades

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.

9/11 permanently changed air travel security in the US

In response to the attacks, the federal government created the TSA, implemented strict passenger screening, reinforced cockpit doors, and banned certain items—transforming airport security into a centralized, high-surveillance system.

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.

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.

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

Passed three days after the September 11 attacks to authorize the use of force against al-Qaeda and the Taliban, the 2001 AUMF has since been stretched far beyond its original scope and has been used by four consecutive administrations to justify military operations.

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 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.

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.

al-Qaeda 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.

President Bush addressed the nation on 9/11 from the Oval Office

Hours after the attacks, President George W. Bush delivered a televised address from the Oval Office, vowing to bring those responsible to justice and characterizing the strikes as an attack on freedom and the American way of life.

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 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.

US intelligence warned of al-Qaeda's plans to strike before 9/11

In the months leading up to 9/11, US agencies received multiple warnings—most notably a CIA memo titled "Bin Laden Determined to Strike in US"—but bureaucratic silos and miscommunication hindered effective action.

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 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.

Smithsonian artifacts that tell the story of 9/11 (w/photos)

Hundreds of objects linked to the attacks, from office supplies recovered at the World Trade Center to firefighters’ gear used at the Pentagon to fragments pulled from the crash site of Flight 93, reside in the national collection. Read about 31 Smithsonian artifacts that help unravel the complex story of 9/11 and its aftermath.

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.

The US and allies invaded Iraq based on flawed WMD intelligence

In 2003, the US—backed by the UK and other allies—launched an invasion of Iraq, citing alleged weapons of mass destruction and ties to terrorism, despite no credible link to 9/11 and the absence of WMDs.

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 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.

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.

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 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.

Late-night comedy—and all media—paused in the aftermath of 9/11

Nearly all entertainment and satire went dark for weeks after the attacks. Jon Stewart's first Daily Show monologue on September 20, 2001, began without an intro, with Stewart speaking through tears about the tragedy.

Questions about the US' commitment to its allies may have sparked a new nuclear age

Some US allies—from Warsaw to Seoul—are reevaluating their security amid doubts over American nuclear commitment, signaling the possibility they may want to acquire their own weapons.

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.

Osama bin Laden declared jihad against the US in a 1997 CNN interview

In a rare public appearance, bin Laden justified his call for armed jihad, condemned US troops in Saudi Arabia, and pledged attacks on American interests, years before the 9/11 attacks.

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

President George W. Bush was reading to second graders in Florida when he was informed that a second plane had struck the World Trade Center, all in view of reporters.

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.

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.

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

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."

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.

How the NSA has changed through history

The National Security Agency was born in the Cold War and then transformed by 9/11. This article answers all the basic questions you might have about the NSA, from what it does to how much data it collects to some of its useful intercepts.

Some scholars consider the Bretton Woods system one of the best foreign policy decisions in US history

A survey of historians by the Council on Foreign Relations ranked the creation of the Bretton Woods system among the top 10 foreign policy decisions in US history, highlighting its role in establishing postwar stability, prosperity, and decades of economic growth.

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.

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

Russian President Vladimir Putin was the first foreign leader to call President Bush on September 12, 2001, offering condolences and support. He visited the U.S. in mid‑November—meeting Bush in Crawford, Texas, and in Washington—to discuss Afghanistan and deepen cooperation in the Global War on Terror.

See how newspapers broke the news of the attack around the world

This collection showcases front pages from cities around the globe reacting to Pearl Harbor in real-time—capturing the shock, fear and uncertainty as the US entered World War II.