9/11: A few hours that changed the United States and the world
September 11, 2001, was one of the darkest days in modern U.S. history and one of the most consequential turning points in international relations. On that day, 19 members of the terrorist organization al-Qaeda hijacked four passenger planes and used them in a coordinated terrorist attack. A total of 2,977 people from 90 countries were killed.
Twenty-five years have passed since the attacks, yet their political, military, and security implications continue to be felt today.
At 8:46 a.m. local time, the first plane, American Airlines Flight 11, crashed into the North Tower of the World Trade Center in New York. Seventeen minutes later, at 9:03 a.m., the second aircraft, United Airlines Flight 175, struck the South Tower. Both towers eventually collapsed. The attacks claimed the lives of 2,753 people in New York.
At 9:37 a.m., the third hijacked aircraft, American Airlines Flight 77, crashed into the Pentagon, the headquarters of the U.S. Department of Defense. A total of 184 people were killed there.
The fourth aircraft, United Airlines Flight 93, did not reach its intended target. After learning about the attacks that had already taken place, passengers and crew members attempted to overpower the hijackers. The aircraft crashed in Pennsylvania, killing all 40 people on board.
In terms of loss of life, 9/11 became the deadliest foreign attack ever carried out on U.S.
According to U.S. and international investigations, the attacks were organized by the al-Qaeda terrorist network under the leadership of Osama bin Laden.
However, the story of 9/11 was not limited to the question of who carried out the attacks. One of the central questions that emerged afterward was why the U.S. intelligence and security apparatus had failed to prevent them.
In 2002, the U.S. Congress and the President established an independent, bipartisan commission to investigate the September 11 attacks. The commission examined millions of documents, interviewed more than 1,200 people, and conducted public hearings. Its final report was released on July 22, 2004.
One of the commission’s key conclusions was that the problem was not simply a matter of individual agencies making mistakes. Information within the U.S. intelligence system often failed to reach the agencies or officials who could have developed a comprehensive picture of the threat. In other words, the system failed to “connect the dots.”
The attacks fundamentally transformed U.S. foreign and defence policy.
Washington declared a global “War on Terror,” and in October 2001, the United States launched military operations in Afghanistan, targeting al-Qaeda and the Taliban regime, which had provided the organization with a safe haven.
The impact of 9/11 subsequently extended far beyond Afghanistan, influencing the Iraq War, the security architecture of the Middle East, U.S. counterterrorism operations, and international military cooperation.
At the same time, the entire U.S. domestic security system underwent major changes. Airport security measures were tightened, intelligence and counterterrorism capabilities were expanded, and in 2002 the U.S. Department of Homeland Security was established.
9/11 changed not only U.S. security policy but also the boundaries of the relationship between the state and the individual.
As part of the fight against terrorism, the government’s surveillance and intelligence-gathering powers were significantly expanded. At the same time, these measures triggered serious debates over human rights, privacy, extrajudicial detention, and the legal limits of counterterrorism efforts.
In this sense, 9/11 left a complex and dual legacy. On the one hand, it forced governments to rethink and strengthen their mechanisms for combating terrorism. On the other, it raised fundamental questions about how far a state can go in the name of national security.
On September 11, 2026, the United States marks the 25th anniversary of the 9/11 attacks.
In the United States, the day continues to be officially observed as Patriot Day, while September 11 is also designated as a National Day of Service and Remembrance.
Today, the site of the former World Trade Center in New York is home to the 9/11 Memorial & Museum, which commemorates all those who lost their lives in the attacks.
