There is only one moment that has been forever seared into the collective memory of living Americans: the horrific terrorist attacks on our homeland twenty years ago on September 11, 2001.

We all know exactly where we were that day. We remember the feelings of confusion as the initial reports came in. The horror of watching fellow Americans jump to their deaths and the towers collapse. The anger at realizing that we were watching an intentional attack. The fear of what would come next. The acts of heroism we witnessed. The unity that followed. The resolve to prevail. The vows to never forget.

If we had known on September 11th that America would not suffer another terrorist attack during the next twenty years, we would have been relieved and even overjoyed. It’s easy to forget that now. Sometime during the past ten or fifteen years, the fear of another major terrorist attack receded. It wasn’t something that average Americans worried about at all. But twenty years ago, in the aftermath of the 9/11 attacks, the single biggest fear gripping America was the fear of another large-scale terrorist attack.

We saw daily warnings and color-coded terrorist threat advisories on our televisions. We worried about how easy it would be for a lone terrorist to detonate a dirty bomb in a crowded metropolitan area. We worried that attacks on our infrastructure could cripple us. We worried about becoming the next victim of terrorism anytime we boarded planes, trains, or even buses. We worried that every crowded sporting event might become a massacre.

For the past two decades, none of that has come to pass. Instead, thousands of our brothers, sisters, sons, and daughters fought the enemy overseas and prevented the fight from coming here. While most Americans returned to their normal lives after the shock of 9/11 wore off, our veterans paid the cost for that normalcy for the next two decades. Nearly 2,500 American veterans were killed in Afghanistan. Hundreds more were injured, and countless others still carry the hidden wounds of war.

Unlike many of America’s past wars, the war in Afghanistan was not supported by a military draft. The soldiers, sailors, airmen, and Marines who fought in Afghanistan were part of an all-volunteer force. Many of those veterans dropped their life plans and enlisted in the military after 9/11 specifically so they could join the fight to defend our nation, our values, and our way of life. They did this even though nobody asked them to and despite the fact that the overwhelming majority of their colleagues and peers did not.

Americans are blessed to have a unique generation of volunteer veterans in our families, communities, and workplaces. As we mark the 20th anniversary of 9/11 and take stock of the past two decades, we should be sure to honor their sacrifices.   

Aaron Rice is an Iraq War veteran and a Purple Heart recipient. He is also the director of the Mississippi Justice Institute, a nonprofit, constitutional litigation center and the legal arm of the Mississippi Center for Public Policy.