For many who served in U.S. Army Counterintelligence (ACI), September 11, 2001 was more than a day of national tragedy that killed almost 3000 people. Many were directly impacted, and, on a CI operational level, it was also a defining moment that reshaped the way ACI confronted terrorism, worked with federal law enforcement partners, and defended the Army at home and abroad. Twenty-five years have passed, and despite all that time, September 11, 2001 can still be remembered in minutes.

• 8:46 AM: American Airlines Flight 11 struck the North Tower of the World Trade Center.

• 9:03 AM: United Airlines Flight 175 struck the South Tower.

• 9:37 AM: American Airlines Flight 77 crashed into the Pentagon.

• 9:59 AM: The South Tower collapsed.

• 10:03 AM: United Airlines Flight 93 crashed in PA after passengers/crew fight back against hijackers.

• 10:28 AM: The North Tower collapsed.

In little more than an hour and a half, 19 al-Qaeda terrorists had transformed four commercial airliners into weapons and murdered 2,977 innocent people. New York's skyline was obscured by smoke and dust. A gaping, burning wound scarred the western side of the Pentagon. A field in rural Pennsylvania became a final battlefield aboard Flight 93. The U.S. had suffered the deadliest terrorist attack in its history and the first foreign strike on U.S. soil since Pearl Harbor. For millions of Americans, the attacks were experienced through television screens and radio reports. For ACI, however, September 11 was also deeply personal and immediately operational. There were ACI Special Agents assigned to the Pentagon when Flight 77 struck with 73 out of the 184 people killed being Army personnel. There were also agents who responded there in the hours and days that followed. Others supported the extraordinary federal response in New York, including work associated with Ground Zero and the massive investigation that followed the destruction of the World Trade Center. Their stories are part of the larger history of ACI after 9/11—a history that, like so much of the profession itself, has rarely been told publicly.

NEVER FORGET—AND NEVER STOP THE MISSION

The history of ACI is not only the history contained in declassified documents, official unit lineages, and published investigations. It also lives in the experiences of the agents who were there. Their memories explain how organizations actually responded when the plans were overtaken by events. Their stories show the next generation what service looked like when the country was attacked. And their experiences help explain why today's ACI enterprise looks the way it does. That is particularly appropriate for the ACISAA, as one of ACISAA's purposes is to preserve the history and heritage of the profession. Twenty-five years after 9/11, that responsibility is more important than ever. “Never Forget” has become the enduring national promise associated with September 11 (also now known as "Patriot Day"). For ACI, those words carry an additional obligation. Remembering means to also remember the victims: the people who went to work in the World Trade Center and Pentagon that morning, the passengers and crews aboard four aircraft, the firefighters and police officers who ran toward danger, the military personnel and federal employees who died at their posts, and the countless families whose lives changed forever.

It means remembering the Americans who responded—including members of our very own ACI community. And, remembrance also means retaining the lessons written in the aftermath. Information must move. Partnerships--like those ACI has with the FBI--matter. Organizational seams are vulnerabilities that adversaries can exploit. The distinction between an intelligence threat and a traditional law enforcement matter can disappear quickly when a hostile foreign actor begins moving towards violence. And preventing the next attack is infinitely preferable to investigating it afterward. We must continue to remember this.

Those lessons helped drive ACI agents into closer relationships with the FBI and the nationwide JTTF network. They sharpened the enterprise's focus on international terrorism while reinforcing the continuing fight against FIE and other national security threats. They helped shape the organization that ultimately became today's ACIC. Twenty-five years after the smoke rose above New York and the Pentagon, the names of organizations have changed and another generation of agents has taken its place. The responsibility has not.

Somewhere today, an ACI Special Agent is working beside an FBI Special Agent on a terrorism investigation. Another is interviewing a source. Another is examining activity involving a FIE actor. Another is briefing an Army commander. Another is following a lead involving an insider threat. Another is trying to determine whether seemingly unrelated pieces of information form something more dangerous. Most Americans will never know their names. That has always been part of the profession. What matters is that they are there. ACI's commitment remains what it was in the days after September 11: to identify and neutralize foreign intelligence and terrorist threats, investigate national security crimes affecting the Army, protect Soldiers and civilians, safeguard Army capabilities, and ensure that those who would harm the United States encounter an enterprise ready to find them before they succeed.

For the agents who were there in 2001, and for those carrying the badge today, September 11 is therefore more than a date to commemorate. It is a reminder of why the mission matters. We remember those we lost. We remember those who responded. And we continue the mission.

Over the next month, the ACISAA will be expanding this article to include more details and recollections of that day from our own Board of Directors who all had already served in the military or were still serving that day. It will be published in the next issue of the Brush-Pass and this post will be updated at that time.

WE WILL NEVER FORGET.