Introduction: Symposium on the War on Terror at Twenty.

• Author: Coyne, Christopher J.

This year marks the twentieth anniversary of the attacks of September 11, 2001 (9/11), and the U.S. government's subsequent "war on terror." The papers in this symposium explore some of the ways that the government response has changed American life over the past two decades.

The 9/11 Attacks and War on Terror

On the morning of September 11, 2001, members of the terrorist group al Qaeda carried out four coordinated attacks after taking control of passenger airplanes. At 8:46 a.m., the terrorists flew American Airlines Flight 11 into the North Tower of the World Trade Center, located in lower Manhattan. A short time later, at 9:03 a.m., they flew United Airlines Flight 175 into the South Tower. Within hours of impact, both towers collapsed. In total, casualties in New York City related to the attacks are estimated at 2,753 people (New York Office of Chief Medical Examiner 2015).

Next, at 9:37 a.m., the hijackers flew American Airlines Flight 77 into the Pentagon located in Arlington, Virginia. The impact, which caused the west side of the building to collapse, killed 184 people (including nonhijacker passengers and crew and those on the ground). United Airlines Flight 93 crashed in a field in Pennsylvania after passengers attempted to regain control of their airplane from hijackers after learning by cell phone about the prior hijackings. The crash resulted in 40 casualties of nonhijacker passengers and crew.

In addition to the aforementioned casualties, thousands of additional people were injured. Many suffered significant negative health consequences due to the inhalation of dust and toxic substances. The full, long-term health consequences are still unknown. The estimated cost of the physical damage in New York City--the World Trade Center and surrounding buildings as well as New York City infrastructure--was $60 billion (CNN 2020).

The attacks resulted in the U.S. government's "war on terror," an open-ended, transnational military campaign to combat terrorism. On September 16, 2001, President George W. Bush (2001b) first referred to a "war against terrorism" during public comments at the White House. Four days later in a formal speech to Congress, Bush made clear that "[o]ur war on terror begins with al Qaeda, but it does not end there. It will not end until every terrorist group of global reach has been found, stopped and defeated" (2001a). With these comments, not only did Bush formally begin the war on terror, but he also set the ambitious benchmark for success--the complete eradication of terrorism.

The war on terror is unique in the history of American wars. There is not a single enemy or clearly delineated battlefield. Instead, the term war on terror refers to a broad collection of government activities spanning the entire globe. Further, there was no specific declaration of war by Congress but instead a broad Authorization for Use of Military Force (AUMF), which became law on September 18, 2001. Under the AUMF, "the President is authorized to use all necessary and appropriate force against those nations, organizations, or persons he determines planned, authorized, committed, or aided the terrorist attacks that occurred on September 11, 2001, or harbored such organizations or persons, in order to prevent any future acts of international terrorism against the United States by such nations, organizations or persons." (1)

The war on terror includes government activities that are both outward facing (outside U.S. borders) and inward facing (domestic activities within U.S. borders). The main outward element consists of wide-ranging international military operations. The most prominent of these military interventions are the invasion of Afghanistan (Operation Enduring Freedom), beginning in October 2001, and the invasion of Iraq (Operation Iraqi Freedom), beginning in March 2003. Other U.S.-led military operations falling under the Operation Enduring Freedom banner include Operation Enduring Freedom--Trans Sahara, focused on the Sahara/Sahel region of Africa; Operation Enduring Freedom--Horn of Africa; and Operation Enduring Freedom--Philippines. The U.S. government has also carried out military 1 strikes in Yemen, often using drones (unmanned aerial vehicles), which have become a key military instrument of its war on terror.

The rise of the Islamic State of Iraq and Syria/Islamic State of Iraq and the Levant (ISIS/ISIL) in 2014 resulted in...