The terrorist organization responsible for the attacks on September 11, 2001, was al-Qaeda. Here's why:
1. Background: Al-Qaeda is a militant Sunni Islamist extremist group founded by Osama bin Laden. The group has been responsible for numerous attacks around the world.
2. September 11, 2001: On that day, al-Qaeda orchestrated a series of coordinated terrorist attacks on the United States. The attacks involved hijacking four commercial airplanes, with two of them crashing into the Twin Towers of the World Trade Center in New York City, one crashing into the Pentagon in Arlington, Virginia, and the fourth crashing into a field in Pennsylvania.
3. Impact: The September 11 attacks resulted in the loss of thousands of lives, extensive damage to property, and had a profound impact on global politics and security measures.
In conclusion, al-Qaeda was the terrorist organization behind the tragic events of September 11, 2001, which remain a significant and somber part of modern history.