25 years after 9/11, the ‘War on Terror’ may be over, but its legacy continues to haunt

6 min readSep 11, 2026 06:32 PM IST First published on: Sep 11, 2026 at 06:32 PM IST

No event has shaped the international security paradigm and geopolitics as much as the 9/11 terror attacks in the US. Al Qaeda (AQ) terrorists used passenger planes as “flying” improvised explosive devices (IEDs), crashing two into the World Trade Centre (WTC) in New York, where about 50,000 people worked. They crashed another one into the western wing of the Pentagon, while passengers managed to overpower the terrorists aboard the fourth “flying” IED heading for the US Capitol Building, and force-crashed the plane in a field in southern Pennsylvania. In all, about 3,000 people died, and 6,000 were injured. Over 2,600 American nationals and 400 nationals of 90 other countries were killed in the attacks.

Nineteen Arab terrorists, including 15 Saudi nationals, carried out the attacks ordered by AQ chief Osama bin Laden (OBL), a Saudi national who was operating from his headquarters in Afghanistan as a “guest” of the Taliban 1.0. The US launched a global “War on Terror” (WoT), which began with the occupation of Afghanistan after the removal of the Taliban in December 2001, a worldwide effort to dismantle AQ’s network, and the occupation of Iraq after the removal of Saddam Hussein in March 2003. The WoT has ended, but not the fight against terror, especially in South Asia.
The sheer audacity and destruction of 9/11 woke up the world to the existence, reach, and capability of AQ’s network. The global community, including non-Western powers like China and Russia, aligned their counter-terrorism (CT) objectives with those of the US when the war in Afghanistan began. About 50 countries contributed troops to US and NATO-led military efforts. However, the US war in Iraq, which involved the mobilisation of thousands of US troops from Kuwait into Iraq in March 2003, was supported largely by the British troops.