The primary cause of the September 11 attacks in 2001 was rooted in a complex interplay of geopolitical factors, extremist ideologies, and grievances against U.S. foreign policy. The attacks, orchestrated by the Islamist extremist group al-Qaeda, were fueled by opposition to U.S. military presence in the Middle East, particularly in Saudi Arabia, and American support for Israel in the Israeli-Palestinian conflict. The attackers sought to provoke fear and gain attention for their anti-Western sentiments. These events led to significant changes in U.S. foreign and domestic policy, prompting the War on Terror, military interventions in Afghanistan, and heightened security measures, fundamentally reshaping global relations and American society.