#104 Derik Kearns - Army Infantry SGM
The Essence of Military Leadership: Lessons from the Frontlines
Featuring SGM Derek Kearns | Tales of Leadership Podcast Ep. 104
Leadership in uniform isn’t just about tactics—it’s about people. In Episode 104 of Tales of Leadership, I sat down with SGM Derek Kearns, a 22-year Army veteran, to uncover the lessons forged through combat, mentorship, and a career defined by consistent growth and impact.
Derek’s leadership journey began in January 2002, post-9/11, when he enlisted in the Army and remained with the same infantry company through three deployments. From Private Second Class to Staff Sergeant, he grew within one unit culture—an incredibly rare opportunity. That consistency gave him a leadership laboratory, where he refined his philosophy in the same environment, deployment after deployment.
His approach to leadership is built on ruthless attention to detail. During his time in Afghanistan’s dangerous Maywand district, Derek leaned heavily into pre-combat checks (PCCs and PCIs). He wasn’t micromanaging—he was eliminating variables that could cost lives. “By the time I got there, I expected nothing left to find—and there always was.” It was that level of focus that made the difference in one of the most dangerous places on earth.
Derek also had to evolve. Transitioning from a light infantry unit to a mechanized Stryker formation challenged him to adapt. His direct, fire-and-forget style needed refinement. He learned to read the room, adjust his delivery, and stay true to his principles while flexing his method. This ability to adapt without compromising values is a leadership muscle too many ignore—and one that Derek built through lived experience.
One of his most powerful roles came as a Ranger Instructor, where he had the chance to influence future leaders under pressure. His evaluation mindset wasn’t about just checking boxes—it was about trust. “I’m not certifying you as a Ranger. I’m certifying that if you were my squad leader on patrol, I wouldn’t want to kill you.” In that one line, he captured what real leadership evaluation looks like: honest, raw, and rooted in reality.
Perhaps the most memorable quote from our conversation was this: “You use machines. You lead people.” It’s simple but powerful. Machines get operated. People get led. Great leaders know the difference—and they invest the time to learn what makes each of their people tick. According to Derek, that investment is what separates good leaders from great ones. You can’t mass-produce trust and influence. You earn it, one moment at a time.
Throughout his career, Derek consistently punched above his weight. He stepped into responsibilities before the rank showed up, and that mindset—lead first, get recognized later—echoes the Army’s leadership pipeline. As he prepares to attend the Sergeant Major Academy, he remains a clear example of what it means to stretch your capacity, own your lane, and lead with purpose.
Final Thoughts
SGM Derek Kearns doesn’t just talk about leadership—he lives it. His story is a blueprint for those looking to lead in high-stakes environments: stay grounded in standards, lead people not processes, adapt when necessary, and always—always—invest in those you serve. Whether you’re wearing a uniform or not, these principles apply. Leadership is less about position and more about posture.
After Action Review
What details in your leadership environment are you overlooking that could be costing you trust or performance?
Are you adapting your leadership style to the environment—or forcing the environment to adapt to you?
Who are you investing in right now, and do they know it?
Together, we will impact 1 MILLION lives!!!
Every day is a gift; don't waste yours!
Joshua K. McMillion | Founder MLC
More Exclusive Content
SGM Derek Kearns shares hard-won lessons from over two decades in the Army—covering attention to detail, adaptive leadership, and investing in people. From combat zones to Ranger School, this episode unpacks what it really means to lead with purpose under pressure.