When you enlist and take the oath of service, you take the oath by yourself, but not on your own. The oath implicates not only your family and friends, but also your future spouse and children, it implicates people you haven’t yet met and, in the case of a distant enemy, people you may never meet.

Tom Satterly fought in the Battle of Mogadishu and ran the “Mogadishu Mile” as part of his first deployment as a Delta soldier. It was the first in a special operations career that spanned into the War on Terror, including the capture of Saddam Hussein and combating the new enemies who tried to fill the power vacuum the toppled leader left. In the end, though, is the question of how a special forces operator copes with reintegrating into a society that doesn’t need specially trained soldiers.

During one of the most storied firefights in recent U.S. history, nine special forces soldiers held a house in Somalia, guarding one of the Black Hawk helicopters that had crashed during a routine operation.In the first of a two part series, retired Delta operator and author of “All Secure” Tom Satterly talks about his induction into the unit and the first combat experience in what would be a 20 year career spanning from the Battle of Mogadishu through the height of the war in Iraq.

Even when you spend the better part of your adolescence dreaming about warfare, and your teens preparing for it, there still is an unnavigable distance between theory and practice, especially when there isn’t even a war on. You attack enemies that aren’t just phantasms, but phantasms without nationality or goal, just representatives of the vague threat you’re trying to thwart. But when the war and the enemy are real, it is nothing like you possibly could have imagined.

Cowardice and recklessness are opposite reactions to the same inclination: putting your wants before the needs of the people you have promised to be faithful to. With Daniel Knapp it is more than that. There is an element of wanting to both emulate and get the respect of those above him. But for Knapp the people above him aren’t the people in charge, they are the people who are better Marines than he is. Those are the people whose approval he craves, because he knows what it means to get it.

The flag-draped coffin is one of the most enduring symbols of war. It is a reminder of the cost and also of the responsibility that young men and women take on as part of their service to their country. Brandon Mitalas enlisted in the Marine corps reserves for selfish reasons, but by the time he had sent 226 marines and sailors home under the stars and stripes, he truly understood the weight of remaining always faithful. He also understood something else: Sometimes it isn’t about you.

Most of the time when we do something, we’re either doing it for us or for someone else, but in the case of our duty, things can get a little less clear. You see, when duty is the thing we’re doing we kind of are doing it for everybody, to live up to a promise we made that we would fill a specific role in our society. Kenny Lyon was all about finding roles and filling them. Whenever he could see the world as a set of instructions, he could follow along nicely, and that got him pretty far as a Marine. One of the toughest requirements he had to meet, though, was figuring out how to go beyond instructions, to see them as a template, but to make your life your own. Doing that takes its own particular gift.

Kristofer Baskett was 19 years old when he arrived in Iraq. He had enlisted in the Navy with his sights on underwater demolition but a little more than a year later he was a corpsman doing his best to fit in with the more seasoned Marines to whom he had been attached. The thing is, when you enlist and accept your trajectory there isn’t much more you can do than go with it. As a Navy corpsman Kristofer hadn’t expected to be doing much fighting, but he learned quickly that combat was a school all its own.

From early on in her training, Vanessa Mahan learned that being an aviator is more than just a test of strength and stamina, it also requires an unrelenting will and focus. What it requires most of all is the ability to shoulder the heavy burden of life and death for dozens of people every time you’re on a mission. On each approach timely action against the enemy ends in casualties or at least a routing on their side. Untimely action can cost American lives. But when you strap in and take off, all you have is the focus and training that brought you as far as you’ve come and the fortitude to try and push it farther.

When Shane Shelton had to delay his entry into the special forces to go and fight in Afghanistan the only thing that buffered his disappointment was that he would get the chance to fight. He had joined the army with an eye on putting his physical prowess to good use, but as he would come to find out, being in top physical condition is secondary once the shooting starts. Keeping a cool head and believing in your mission and in your battle buddies, especially when things get bleak requires the kind of mental toughness you can only perfect once the bullets start flying.