It’s been 18 years since one of the worst days in American history. We soon will graduate the first high school class that wasn’t around — much less aware of — the day of the 9/11 attacks.

War came to our shores that day, in New York City, our nation’s capital and a field in rural Pennsylvania. There are those instances when you will remember clearly where you were and what you were doing. For many of us, that morning of 9/11 is just such an occurrence.

Since the morning of Sept. 11, 2001, we have been engaged in a global war on terror. It has led the United States to send troops to fight in remote corners of the world, most notably Afghanistan. 

You could argue the point at which the war really started. Did it start as far back as 1983, when suicide bombers struck the Marine barracks in Beirut, or on the first attempt to bomb the Trade Center towers in the 1990s?

Since Al Qaeda’s strike against the U.S. 18 years ago, our nation has been involved in combatting terrorism in more than 80 counties and on six continents, according to the Smithsonian Magazine and Brown University’s Costs of War Project. 

At the height of Operation Enduring Freedom (now Operation Freedom’s Sentinel), there were more than 100,000 U.S. troops in Afghanistan alone. That number has been reduced significantly over the years, but there are still close to 14,000 American men and women serving there. Since the start of combat operations several weeks after the 9/11 attacks, nearly 1,900 Americans have been killed in action in Afghanistan.

Nearly 3,000 Americans and others died on this day 18 years ago in an attack upon our freedom and values. Since then, Al Qaeda and other terrorist groups have struck or tried to initiate attacks, but not on the scale of what happened on 9/11. 

Our freedoms and values, though, have withstood them. It has been a long and costly war but that which has made us the greatest nation on the face of the Earth is worth defending. Al Qaeda and other groups may seek to strike down the United States in the future. But they didn’t succeed 18 years ago and as long as continue to treasure our freedom and our values, and as long as men and women stand up for them, they never will.