It has been nearly 20 years since Al Qaeda operatives carried out the deadliest terror attacks on America in the country’s history, killing nearly 3,000 people and injuring thousands more.

Today the complex legacy of the Sept. 11 attacks and the U.S.’s ensuing “war on terror” is still unfolding, from the bloody conflicts in Afghanistan, Iraq and beyond to division and distrust at home.

Tonight, Sept. 7, at a special time — 9/8c — we’ll present America After 9/11, an epic re-examination of the decisions that transformed the U.S. and changed the world.

With extraordinary access to key participants and decision-makers, this two-hour documentary special from acclaimed FRONTLINE filmmaker Michael Kirk and his team traces the response to the terror attacks and the compromises and consequences for American democracy across four presidencies.

“Our new documentary offers a powerful historical record of how 9/11 ushered in an era of fear, mistrust and division in America — one that would ultimately see the Capitol once again being targeted, and democracy itself coming under assault,” says Michael.

With his team, Michael has made more than 30 documentaries chronicling 9/11; the Bush, Obama and Trump administrations; and the post-9/11 wars in Afghanistan and Iraq.

“Our reporting has shown that only by tracing 9/11’s complex legacy can we fully understand the path to the present — from the values compromised, to the trust eroded, to the wars abroad, to the insurrection at home,” he says.

As the country prepares to mark the 20-year anniversary of the attacks, America After 9/11 is urgent and essential viewing.

America After 9/11 premieres tonight at 9/8c on PBS stations (check local listings) and on FRONTLINE’s YouTube channel, and will be available to stream starting at 7/6c in the PBS Video App and in our online collection of documentaries.

Plus: In the runup to the 9/11 anniversary, we’ve selected 17 documentaries from two decades of extensive FRONTLINE reporting that probe that fateful day, investigate the cascade of decisions that followed and trace the lasting impact on America and the world.

These films are now streaming here, as part of our digital collection and on the PBS Video app — several for the first time in years. In addition, many are now available to watch on our YouTube channel, with more films added biweekly through the anniversary this Saturday.

Thank you for watching.