Nor could the leaders and policymakers who reacted to the events of that horrible day. Those who planned and implemented the horrendous attacks of 9/11 could not have imagined all the ways that their attempt to sow chaos would change the world. In observance of the anniversary, BU Today reached out to faculty across Boston University-experts in international relations, international security, immigration law, global health, terrorism, and ethics-and asked each to address this question: “How has the world changed as a result of 9/11?”

It reshaped US immigration policies and led to a surge in discrimination, racial profiling, and hate crimes. The events of 9/11 not only reshaped the global response to terrorism, but raised new and troubling questions about security, privacy, and treatment of prisoners. Nearly 3,000 people were killed that day and the United States soon found itself mired in what would become the longest war in its history, a war that cost an estimated $8 trillion. In the space of less than 90 minutes on a late summer morning, the world changed. A third plane, American Airlines Flight 77, leaving from Dulles International Airport in Virginia, crashed into the Pentagon at 9:37 am, and the final plane, United Airlines Flight 93, departing from Newark, N.J., crashed in a field in Shanksville, Pa., at 10:03 am, after passengers stormed the cockpit and tried to subdue the hijackers. Two planes-American Airlines Flight 11 and United Airlines Flight 175-departed from Boston and Flight 11 struck New York City’s World Trade Center North Tower at 8:46 am and Flight 175 the South Tower at 9:03 am, resulting in the collapse of both towers. On that Tuesday morning, 19 al-Qaeda terrorists hijacked four American commercial flights destined for the West Coast and intentionally crashed them. Saturday, September 11, 2021, marks the 20th anniversary of 9/11, the largest terrorist attack in history.

911 aftermath