Answer: September 11
The September 11 attacks (also known as 9/11) were a series of coordinated attacks against the United States on September 11, 2001 by the Islamic terrorist group Al-Qaeda.
The War on Terror is a military campaign launched by the United States. The first time the term was used was by President George W. Bush on September 16, 2001. The term has been particularly linked with al-Qaeda, although it has also been criticized because of its lack of clarity.