What event on September 11, 2001 led the United States to launch the War on Terror?

• A. The assassination of Osama bin Laden
• B. The bombing of Pearl Harbor
• C. Terrorist attacks on the World Trade Center and the Pentagon
• D. The invasion of Afghanistan

Answer: (C)

A defining crisis can shift a nation’s security policy. On September 11, 2001, terrorist attacks on the World Trade Center and the Pentagon demonstrated how deeply vulnerable the United States could be to coordinated terrorism, prompting a broad, long-term response—the War on Terror. This marked a move from reactive security measures to a proactive, global effort to disrupt terrorist networks, prevent attacks, and reshape U.S. military and diplomatic strategy. A key part of the response was military action in Afghanistan starting in October 2001 to dismantle al-Qaeda and remove the Taliban from power, which had provided a sanctuary for the group. The other events don’t fit the trigger for this policy shift: the assassination of Osama bin Laden occurred years later and was not the initiating event; the bombing of Pearl Harbor happened in a different era and context; and while the invasion of Afghanistan followed the attacks, it was the attacks themselves that spurred the War on Terror.