The events of September 11, 2001, had a profound global impact, particularly on international security and foreign policy. The terrorist attacks perpetrated by al-Qaeda led to heightened fears of terrorism and prompted the United States to initiate the War on Terror. This included military interventions in Afghanistan and Iraq and extensive security measures worldwide, affecting civil liberties and international relations. The attacks also resulted in increased surveillance and intelligence-sharing among nations, altered global perceptions of security threats, and significantly impacted diplomatic and military strategies for years to come.