The terrorist attack on the United States on Sept. 11, 2001, had a profound lasting effect on our legal system and our society. As the first major foreign attack on American soil since the bombing of Pearl Harbor, it caused a fundamental shift in law enforcement.
Society wanted the government to do what was necessary to prevent future attacks, not just to have the police solve crimes and provide the evidence for prosecutions. This needed to be the responsibility of the federal government, not of state and local police departments. The enemy was not a foreign country, but a terrorist organization, al-Qaida. And there was every reason to believe that the war on terrorism would continue indefinitely into the future. Together, these factors had enormous effects.
Authorization for the use of military force
On Sept. 14, 2001, Congress passed an AUMF, a joint resolution of the House and the Senate that authorized the president to use all necessary and appropriate force against those responsible for the attacks as well as any organizations or people who aided or harbored them. This AUMF was an expansive delegation of power to the president to use military force, and it had no expiration date. It was used by President George W. Bush and his successors to justify military interventions in various countries, including Afghanistan, Iraq and Syria.
Enemy combatants, Guantánamo and torture
Soon after 9/11, the United States began apprehending those it believed were part of al-Qaida. President Bush and his administration took the position that these individuals, including American citizens detained in the United States, could be held indefinitely as “enemy combatants.” This is a category that did not exist in international or American law.
In Hamdi v. Rumsfeld in 2004, the U.S. Supreme Court held that the 2001 AUMF authorized detaining an American citizen in the United States as an enemy combatant, but that the person needed to be given due process of law. At a minimum, this included notice of the charges, a meaningful factual hearing and representation by counsel. The case involved Yaser Hamdi, an American citizen apprehended in Afghanistan and held at a military prison in South Carolina. After the Supreme Court’s decision, the government released Hamdi on the condition that he renounce his citizenship, leave the country, renounce terrorism and waive his right to sue the United States.
In January 2002, there were the first reports of men being brought —shackled, blindfolded, and drugged—to an American military base in Guantánamo Bay, Cuba. A total of 780 prisoners were held in Guantánamo, and 15 are still there now, 25 years after 9/11. The government did not want to try these individuals in federal courts, where all of the constitutional protections would apply, but instead in military tribunals where it thought it had a greater likelihood of prevailing. Only a few trials have yet been held.
The Bush administration vehemently argued that Guantánamo detainees should have no ability to go to federal court on a writ of habeas corpus to challenge their detention. Congress passed two laws, the Detainee Treatment Act and the Military Commissions Act, barring Guantánamo detainees from filing habeas corpus petitions. But the Supreme Court in Rasul v. Bush (2004) held that Guantánamo detainees could bring habeas corpus petitions, and in Boumediene v. Bush (2008) ruled that barring habeas corpus petitions was unconstitutional. After that, however, the court did not take another case from Guantánamo detainees, even when lower federal courts refused to hear their habeas corpus petitions.
We now know that some held in Guantánamo were there by mistake. We also know that many in Guantánamo, Abu Ghraib, and other sites across the world were brutally tortured. Attorneys in the Justice Department’s Office of Legal Counsel wrote a series of memos—often referred to as the “torture memos”—saying the president could redefine torture, which is prohibited by United States and international law. These memos provided legal justification for the use of “enhanced interrogation techniques” such as waterboarding, sleep deprivation and stress positions on detainees held in custody during the war on terror.
A report of the Senate Intelligence Committee, released in December 2014, describes horrific, sadistic brutality inflicted on prisoners. It also leaves no doubt that both United States criminal statutes and international treaties were violated. The 499-page report describes in detail what was done. The report tells of a man chained to a wall in the standing position for 17 days and of detainees kept awake for nearly 180 hours in standing or stress positions.
The report also documents repeated waterboarding, which international law has long defined as torture, including one man who was waterboarded 183 times. It tells of detainees being immersed in ice baths and of the killing of an Afghan, Gul Rahman, who died of suspected hypothermia in November 2002 after he was stripped naked from the waist down and left chained to a concrete floor in near-freezing temperatures. The report details forced rectal feeding, which is described as intensely painful and obviously is enormously degrading.
Lawsuits brought by victims of torture were dismissed by federal courts of appeals on the grounds of the “state secrets privilege,” which broadly permits the government to prevent disclosure of information that it believes would harm national security interests. For example, Khaled El–Masri sued federal government officials who he claimed were responsible for his being abducted, imprisoned for 150 days in a CIA-operated detention facility in Afghanistan, drugged, and tortured. He was released when it was discovered that it was a case of mistaken identity; he was confused with someone with a similar name. But the Richmond, Virginia-based 4th U.S. Circuit Court of Appeals said his case had to be dismissed because of the state secrets privilege.
The consequences of the government’s engaging in torture continue to arise. Last Friday, Aug. 28, a military judge ruled confessions made by alleged 9/11 mastermind Khalid Sheikh Mohammed to FBI agents are inadmissible at trial because they were tainted by the CIA’s torture of him.
The USA Patriot Act
The law was adopted on Oct. 26, 2001, to expand the powers of law enforcement and intelligence agencies to prevent future terrorist attacks. It allowed for increased surveillance of individuals suspected of terrorism or related activities, expanded the government’s ability to track and intercept communications, and enhanced information-sharing between government agencies. It authorized the use of National Security Letters to compel businesses to turn over customer information without judicial oversight.
Section 215 of the Patriot Act, which expired in 2020, gave law enforcement broad authority to obtain secret court orders compelling third-party entities to produce “any tangible thing” relevant to international terrorism or foreign intelligence investigations. It allowed the FBI and intelligence agencies to demand broad categories of records—including business, financial, medical, internet and library records—without showing probable cause of a crime. And it put the recipients of the orders to turn over the requested items under a gag order, making it illegal for them to disclose that the government had sought or obtained the records.
The Department of Homeland Security
In 2002, Congress passed and President Bush signed the Department of Homeland Security Act, which combined 22 separate federal agencies into one cabinet-level department to protect the country and manage emergencies. It is the third-largest federal cabinet department.
The following year, Congress created the U.S. Immigration and Customs Enforcement as part of the Department of Homeland Security. ICE was created in the post-9/11 restructuring of the federal government and combined the investigative and enforcement elements of the former Immigration and Naturalization Service and the U.S. Customs Service. It has been massively expanded under President Donald Trump.
Conclusion
It is impossible to make an overall assessment of all that was done after 9/11. There is no way to know what terrorist activities were prevented because of the greater law enforcement authority that was created in response to 9/11 or how many lives were saved. There is no way to know whether the United States would have entered into the disastrous wars in Afghanistan and Iraq without the 2001 AUMF. There is no way to assess the loss of privacy as a result of the legal authority given to the government after 9/11. There is no way to know the loss of moral authority that the United States suffered because of Guantánamo and the torture there and elsewhere. The only possible conclusion is that 9/11 led to myriad changes in the law that last to this day.
Erwin Chemerinsky is dean of the University of California at Berkeley School of Law. He is an expert in constitutional law. He’s also the author of many books, including his most recent ones: Campus Speech and Academic Freedom: A Guide for Difficult Times and The Supreme Court October Term 2024: Taking Sides.
This column reflects the opinions of the author and not necessarily the views of the ABA Journal—or the American Bar Association.
Facts Only
* September 11, 2001: Terrorist attack on the United States occurred.
* September 14, 2001: Congress passed the AUMF authorizing the President to use necessary and appropriate force against those responsible for the attacks or those who aided them.
* The AUMF authorized the use of military force, which was used to justify military interventions in Afghanistan, Iraq, and Syria.
* Following 9/11, the U.S. began apprehending individuals believed to be part of al-Qaida.
* Detainees were held as "enemy combatants," a category not existing in international or American law.
* In *Hamdi v. Rumsfeld* (2004), the Supreme Court held that detention under the AUMF required due process, including notice, a hearing, and counsel.
* 780 prisoners were held in Guantánamo Bay, Cuba; 15 remain there 25 years later.
* The Detainee Treatment Act and Military Commissions Act barred Guantánamo detainees from filing habeas corpus petitions.
* The Supreme Court in *Rasul v. Bush* (2004) and *Boumediene v. Bush* (2008) addressed habeas corpus rights for detainees, though subsequent action was limited.
* "Torture memos" were written by the Justice Department’s Office of Legal Counsel, providing legal justification for "enhanced interrogation techniques" like waterboarding.
* A 2014 Senate Intelligence Committee report documented brutality inflicted on prisoners, including instances of waterboarding and other severe physical treatment.
* Lawsuits against officials regarding torture were dismissed by federal courts of appeals based on the "state secrets privilege."
* A military judge ruled confessions obtained from Khalid Sheikh Mohammed inadmissible because they were tainted by CIA torture.
* The USA Patriot Act was adopted on October 26, 2001.
* Section 215 of the Patriot Act allowed for the compelled production of records without probable cause and imposed gag orders.
* The Department of Homeland Security Act was passed in 2002 to combine 22 federal agencies.
* Immigration and Customs Enforcement (ICE) was created as part of the Department of Homeland Security.
Executive Summary
The 9/11 attacks prompted a fundamental shift in law enforcement, leading to the view that responsibility for preventing future attacks should rest with the federal government rather than state and local police. This necessitated the authorization of military force via the Authorization for Use of Military Force (AUMF) passed by Congress on September 14, 2001, which granted broad authority to the President to use military force against those responsible for the attacks or those who aided them, without an expiration date.
Following the attacks, the United States began apprehending individuals believed to be part of al-Qaida, leading to the classification of some detainees as "enemy combatants," a status that initially did not exist in established international or American law. This categorization led to the detention of men, including American citizens, such as Yaser Hamdi, in facilities like Guantánamo Bay, Cuba. Legal challenges regarding this detention evolved through cases like *Hamdi v. Rumsfeld* and later decisions concerning habeas corpus petitions, culminating in rulings that barred certain detainees from filing such petitions.
The administration also authorized the use of "enhanced interrogation techniques," including waterboarding and stress positions, on detainees. Subsequent Senate Intelligence Committee reports detailed severe brutality inflicted upon prisoners, documenting practices that violated international law, including torture. Legal challenges against these actions were often dismissed under state secrets privilege, though later developments saw some shifts, such as a military judge ruling confessions obtained through torture inadmissible. Furthermore, legislation like the USA Patriot Act expanded surveillance powers, notably Section 215 of the Patriot Act, which allowed for broad demands of records without traditional judicial oversight. The Department of Homeland Security was established in 2002, and Immigration and Customs Enforcement (ICE) was created as part of this restructuring.
Full Take
The narrative emerging from the post-9/11 legal and executive actions reveals a deliberate, high-stakes redefinition of governmental authority rooted in security concerns. The transition involved shifting responsibility for counter-terrorism from local law enforcement to federal military action, institutionalizing an expansive power structure via the AUMF that remains a source of tension regarding civil liberties. The handling of detainees in facilities like Guantánamo exemplifies how legal categories can be created and maintained outside traditional jurisprudence, especially when balancing national security imperatives against established constitutional norms like due process.
The documented use of extraordinary interrogation techniques and the subsequent failure of legal mechanisms—such as habeas corpus challenges and post-torture lawsuits dismissed under state secrets privilege—suggest a pattern where existential threats are used to justify actions that inherently challenge fundamental principles of justice and human dignity. The fact that evidence regarding torture was systematically suppressed, as seen in the Senate report and subsequent litigation, highlights a systemic preference for state secrecy over accountability. Furthermore, the expansion of surveillance powers through legislation like the Patriot Act demonstrates a mechanism by which broad security mandates can be legally implemented, potentially creating enduring structures that limit individual agency post-event.
The ultimate implication is that profound legal changes resulting from 9/11 were not merely reactive measures but created structural precedents that allow for significant executive and intelligence power expansion with relatively limited judicial constraint. The persistence of these systems, despite documented atrocities and legal challenges regarding accountability, suggests a powerful tension between the perceived necessity of security and the protection of established civil liberties and moral authority. What questions remain open about how societies reconcile necessary security measures with the enduring principles of law and human rights when faced with state-sanctioned exceptionalism?