Forged in response to the Palmer Raids of 1919, the American Civil Liberties Union has learned the hard way that civil liberties and human rights are the first to go when war fever strikes. We fought against Japanese American internment, lived through McCarthyism and House Un-American Activities investigations, and challenged FBI’s COINTELPRO abuses.

One week before the tragic 9/11 attacks, I started a new job as head of the ACLU. While I was still new and unsure, the organization itself had weathered many prior crises, but none quite like this. As we mark the 20th commemoration of 9/11, the fight for human rights and civil liberties continues to this day.

Three lessons from the “war on terror” should guide us. First, we must remember that the American public has a conscience and can be activated to use it. Second, civil society and the courts have a vital role to play as a bulwark to government overreach. And finally, we need to realize the damage wrought after 9/11 runs deep. After 20 years, it’s not possible to simply turn the page. There’s too much still left to be undone.

In the wake of 9/11, an alarmed Congress rushed to pass the USA Patriot Act, ushering in a new era of mass surveillance. Only one Senator—Russ Feingold—had the courage to vote against it. The act passed 35 days after the attacks and was 342 pages long. Members of Congress later admitted to not understanding or even having read it before voting on the bill. A few liberal senators confided to me at the time that they felt a pressure to “stand united” and support President Bush in that moment of national tragedy.

Initially, members of the media also gave the government the benefit of the doubt. One NPR correspondent said privately to me that America needed to do everything we could to stop the next terrorist attack, arguing that the ACLU’s hard-line defense of civil liberties was wrongheaded. Other news outlets were slow to cover the civil liberties issues arising out of the 9/11 attacks.

Over time, public perception of the “War on Terror” would change. Local “Bill of Rights Defense” committees started a grassroots groundswell to condemn the Patriot Act in more than 400 communities. Details emerged about what the war actually entailed—mass deportations; rampant racial, ethnic, and religious profiling; FBI demands for “voluntary” interviews of young Muslim, South Asian, and Arab men; secret “black sites” into which the CIA disappeared suspects; torture; renditions of suspects to countries that would torture them for us. Each revelation helped shift unwavering support for the War on Terror to skepticism of government overreach. When the Abu Ghraib photographs came to light in April 2004, America’s collective conscience began to kick in. And a major inflection point came in December 2004, when the ACLU began disclosing documents secured under the Freedom of Information Act (FOIA) detailing the widespread use and sanctioning of torture. Only then did the tenor of policy debates on some of the most egregious abuses fundamentally shift.

While Congress panicked and the Bush administration took the country to war, civil society and the courts played key roles in protecting our democracy. In the early aftermath of 9/11, the ACLU wielded the FOIA aggressively—seeking to release government documents on everything from racial profiling to surveillance to torture. We used the FOIA as “democracy’s X-ray”—to extract information from a secretive government that was obfuscating how it was waging its War on Terror. We successfully brought one of the first legal challenges to the Patriot Act on behalf of a group of librarians.

The Center for Constitutional Rights courageously challenged the detentions of “enemy combatants” at Guántanamo Bay. Human Rights Watch and Amnesty International argued for accountability for torture. The ACLU and other groups filed multiple suits on behalf of torture survivors. The high-water mark of courts’ decisions came by 2008, once the US Supreme Court ruled that Guantánamo was not the legal black hole Bush, Ashcroft, and Cheney intended it to be. Unfortunately, more than a decade later, we are still fighting many of these same battles.

Thirty-nine Muslim men remain indefinitely detained at Guántanamo—some have been cleared for release for years, and several have never been charged with a crime.

Those who have been charged face trial not in an ordinary criminal court but in an unprecedented “military commission.” I attended the first arraignment in Guántanamo back in 2004, and it was clear to me then that the military commissions could never render any acceptable version of actual justice. The prosecutors still seek the death penalty in proceedings without regard for basic protections guaranteed by the Constitution. And the US government has spent billions of dollars on this failed and irretrievably doomed legal experiment. It’s long past time for President Biden to shutter the military commissions, close Guántanamo, and end indefinite military detention.

The government still uses the “no-fly list,” primarily against Muslims and people of color, and individuals wrongly placed on the list still don’t have a fair process to get off. it. Most of the Patriot Act is still law. We need to reckon with the fact that much of the legal and policy infrastructure adopted in the aftermath of 9/11 remains with us today.

I’ve learned a lot in 20 years about the risks of government overreach, the critical importance of civil society and an independent judiciary, and the enduring legacy ”forever wars” can have. But most of all, I’ve learned that we can and must pursue our security while respecting civil liberties. When we forget that lesson, we come to regret it. The future we want must ground security in human rights, equality, dignity, and accountability, in action as well as words. No exceptions.