The U.S. Defense Department has released the names of the three Marines killed when an improvised explosive device was detonated near Bagram Air Base near Kabul in Afghanistan on Monday.

Staff Sgt. Christopher K.A. Slutman, 43, of Newark, Delaware; Sgt. Benjamin S. Hines, 31, of York, Pennsylvania; and Cpl. Robert A. Hendriks, 25, of Locust Valley, New York were killed by the blast.

All three of these Marines were assigned to the 25th Marine Regiment out of Fort Devens, Massachusetts, a reserve command that falls under the Fourth Marine Division. I’m particularly familiar with that command, as I served as the personnel chief for 25th Marines between 2009 and late in 2012, when I was medically retired from service.

As an active-duty Marine assigned to inspector/instructor duty (commonly referred to as I&I), my responsibilities included training the reserve Marines under my charge in their respective occupational specialties, managing the annual training requirements for the company, and tracking overall training throughout the regiment—alongside the laundry list of I&I-specific responsibilities that included supporting activated units in theater, the active-duty staff throughout the regiment, and of course, serving on the area’s funeral honors and next of kin notification teams.

Serving as an active-duty Marine at a reserve command can be a truly daunting task. On more than one occasion, I recall sleeping under my desk because there was too little time between duty requirements to go home to rest. Most non-drill weekends are filled with funeral services (perhaps other commands are less busy, but many Marines tend to settle near Boston), which included maintaining lines of communication with the next of kin of the deceased—a responsibility that was both an honor and incredibly emotionally taxing.

For most Marines, putting on your dress blue uniform comes once a year: at the Marine Corps Ball. For those of us serving on I&I duty, our blues saw more wear than any uniform outside of our camouflage utilities. Sometimes it was to celebrate the holidays and serve as a representative of the Marine Corps while generous people donated toys for needy kids. Other times it was to bury a young Marine who had taken his own life. On a few rare occasions, the job may have been to do both in the same day.

And throughout it all, there were some Marines who you could count on no matter the time of day, no matter the terrible weather, and no matter their own social and professional obligations. These Marines were the very definition of the Corps’ approach to duty and honor, often going far above and beyond their responsibilities to the command in order to make sure the job, whatever it may be, got done and our Marines were able to go home.

The thing is, these Marines I’m talking about were reservists that had absolutely no contractual obligation to support their brothers and sisters in uniform during non-drill weekends. These Marines all had other jobs, lives, and relationships to contend with. Of all the Marines I’ve served with, met, interacted with, or worked alongside, some of the best I’ve ever come across were part-timers, though “part-time” was a label that rarely extended beyond their duty status. In their minds and hearts, they were Marines. It’s as simple as that.

Among active-duty guys, we’ve been known to pick on our reserve counterparts, and within the reserve community, you’ll find people tend to handle that ribbing in different ways. Among my absolute favorites was the shouted response, “FUBIJAR!” (which is an acronym for “F*ck You Buddy I’m Just a Reservist). Silly as that sounds, it’s in that willingness to find humor that I saw some of the most sincere elements of dedication to our branch and our nation. Those guys who would chuckle and shoot retorts back at us active duty-a**holes were almost always the same guys with their hands in the air when something needed to get done. They were the guys still hanging around headquarters when drill ended, stacking chairs and losing sleep with our active-duty skeleton crew.

Those guys we’d rag on for having the audacity to maintain private sector jobs were the same guys who would show up wearing their (not particularly thick) dress blues in three feet of snow to support a full honors funeral for a man they’d never met, on a day they weren’t required to serve. They were the guys who would accept ADOS (Active Duty Operational Support) orders to burn through their two weeks of vacation time this year to help us get through workups for other Marines to deploy. They were the guys who showed up at drill weekend with bloodshot eyes after working 60 hours the week prior as police officers, firefighters, and school teachers. They were the lifeblood of their communities, and in those brief hours that most in their fields would reserve for rest and recuperation, they were lacing up their boots and heading into the field with us for another training rotation.

Active-duty Marines make great sacrifices in order to serve, and because of those sacrifices, it’s sometimes difficult for us to see and truly appreciate the unique sacrifices our reserve siblings make in their own ways. While not every reservist I met was a Marine worthy of my respect and admiration, in those that were, I found enough heart, pride, and strength to carry this nation through the worst the world could throw at it. I saw a willingness to give their lives for the nation they loved.

And, as we’ve seen this week with three Marines from the very reserve command I once helped train dying in Afghanistan, these Marines face the very same risks as their active-duty counterparts. Their wives, their children, and their communities share in those risks, and we, as a nation, owe a debt to them all.

Slutman, Hines, and Hendriks died fighting a war that many Americans don’t agree with and still more don’t seem to care about at all, but where they died is less important than what they died doing. When most Americans can’t even find time to go to the gym, they surrendered the little time they had outside of work to a cause that was greater than themselves, and now, they’ve sacrificed so much more. All for a nation they love. All for us.

Our country asked them to serve, and like so few Americans, they answered the call. I’m proud to have served in the command from which they hailed. I’m proud to have served alongside Marines I could admire, respect, and emulate in both component codes—active and reserve. Today, through the sadness, the loss, and the pain that is reverberating throughout our nation, I’m as proud as ever to be a Marine.

The truth about reservists is simple: They’re Marines just like the rest of us. In fact, sometimes, they’re the best of us.