When considering the influence of someone like Secretary of Defense Ash Carter, it’s nearly impossible to capture it all in words.

His impressive credentials might leave you feeling somewhat overshadowed. With degrees in physics and medieval history from Yale, he was also a Rhodes Scholar with a doctorate in theoretical physics. Having held every significant position at the Pentagon, he stands as the most qualified Secretary of Defense in U.S. history. A five-time recipient of the Department of Defense's highest civilian honor, he was a professor whose students have risen to prominence in public service. Additionally, he authored eleven books and over a hundred significant articles. He was a devoted husband and father, and this is merely the beginning of his legacy.

Needless to say, it’s easy to feel inadequate in comparison.

Statements from both President Biden and President Obama provide insight into the profound influence SecDef Carter had on them and the world. Yet, there is so much more to his story.

For me personally, there is no one who has impacted my life more over the last decade than Ash Carter. I don’t make that claim lightly, particularly since I’ve had the privilege of working alongside many remarkable individuals.

Initially, I was not supposed to collaborate with SecDef Carter. President Obama had made it clear that my focus should be on domestic policy rather than my national security roots. However, that directive was short-lived. Having previously worked with his wife, Stephanie, I ran into them while they were out walking their dog. Before long, I found myself on his plane for the first trip a Secretary of Defense had made to Silicon Valley in two decades. Little did I know, that journey would provide me with invaluable leadership lessons from one of the greatest Secretaries of Defense and signal the start of significant changes at the Pentagon.

What set SecDef Carter apart was his unique combination of five key traits:

1. Intellectual rigor
2. People and talent
3. Integrity and doing the right thing
4. Passion for everything he engaged in
5. Commitment to public service, mission first, and patriotism

Intellectual Rigor

What did SecDef Carter do in his free time? He learned. I’m not joking; he read textbooks just for fun. He was a relentless learner, delving into subjects like data science, AI, genomics, and healthcare policy. During our regular discussions, I often found myself sharing insights from my latest research, as he was always eager to know more.

I recall one instance where we explored how aerial refueling operated, and before we knew it, SecDef Carter was delivering a detailed lecture on the necessary physics and the advantages and disadvantages of various methods.

Working with him taught me the importance of understanding the intricate details. He emphasized that our responsibilities demanded such depth of knowledge because, as he pointed out, lives depended on it. He expected excellence from those around him, which fostered an environment where everyone thrived.

People and Talent

I wish there were a way to visualize SecDef Carter's network. Not just because of the numerous presidents he served, but due to the vast influence he had on the talent he mentored.

SecDef Carter was first and foremost an educator. He understood that to make a significant impact, he needed to invest time in others. Even amidst the many crises he managed, he always found time for people.

He exemplified the idea of "walking the floor," spending time with those in the most basic roles. I witnessed him regularly engaging with personnel at the Pentagon and dedicating long hours to connect with troops in the field. His visits were not merely for show; he listened intently. If you were nearby, you could expect to be assigned follow-up tasks based on the discussions he had with others. He diligently ensured that we made progress on those fronts.

Integrity and Doing the Right Thing

SecDef Carter was unafraid to speak the truth, even when it was politically uncomfortable. His core belief in doing the right thing guided his actions. I had the privilege of witnessing his effective management of policies that allowed transgender individuals to serve in the military and ensured that women could participate in all combat roles. He championed these changes because he believed they were right, countering excuses with arguments for equality and the notion that a military reflecting the nation would enhance our national security.

SecDef Carter demanded integrity from himself and those around him, and it was one of the reasons I cherished working with him. Collaborating with him meant being part of a team that held itself to the highest ethical standards.

Passion for Everything You Engage In

Some people enjoy their work, while others truly love it. SecDef Carter was in the latter group. His deep passion for learning was rooted in a desire to serve those in uniform, his country, his family, and his students.

In essence, SecDef Carter cared deeply. As the saying goes, “you can’t teach heart.” He had a tremendous heart.

When SecDef Carter interacted with my children, his enthusiasm was palpable. The joy on his face when explaining the importance of our work was unmistakable. Each phone call would start with his trademark greeting, “Hey brother!”

Public Service, Mission First, and Patriotism

SecDef Carter epitomized public service. He poured everything he had into his role, often sacrificing his health for the mission. He and his wife, Stephanie, were staunch advocates for military personnel and their families. He understood the demands of his position and the risks associated with his decisions. He frequently reminded us, “Security is like oxygen; when you have it, you tend not to notice it.”

His patriotism inspired him to challenge his team to leave the Pentagon in a better state than they found it. It was this commitment that allowed him to attract top talent, establishing initiatives like the Defense Innovation Board (DIB), Defense Innovation Unit (DIU), and Defense Digital Service (DDS). He encouraged people to “think outside of the five-sided box,” fostering programs such as Hack the Pentagon. I can confidently state that the nation is more secure due to SecDef Carter’s contributions.

SecDef Carter's influence extended beyond his time at the Pentagon. His recent endeavors at Harvard's Kennedy School and the Belfer Center have generated some of the most insightful discussions on today's pressing issues. The students he has mentored will undoubtedly emerge as influential leaders over the next 50 years, guided by the following principles:

1. The advancement of technology is inevitable, often benefiting some while leaving others behind. We must foresee the challenges posed by emerging technologies and work towards solutions.
2. There is no easy fix; effective responses to technology-related public dilemmas require a combination of government regulation and self-governance in the tech sector. The optimal balance can only arise from robust and trusted connections between government and the tech community.
3. To foster a future driven by public purpose, we must inspire and prepare the next generation of tech leaders to implement sustainable solutions.

If you wish to grasp the extent of SecDef Carter's influence, I recommend his latest book, Inside the Five-Sided Box: Lessons from a Lifetime of Leadership in the Pentagon, or his Drell Lecture delivered at Stanford University.

Personally, I have gained countless insights from SecDef Carter, and I hope to share those stories to benefit others. One of the most unforgettable moments occurred in his final weeks as Secretary of Defense. He summoned me to the Pentagon for an urgent matter while I was already exhausted, with my family back in California for the new school year. I rushed over, canceling all other engagements, only to find my entire family, White House colleagues, and Pentagon associates waiting for me. SecDef Carter and his team had orchestrated this surprise while he presented me with the Department of Defense Distinguished Public Service Medal (the same one he has, except he holds five). Having my children witness that moment was an incredible gift, made even more meaningful by the knowledge that our collective work had a positive impact on the country. That work would not have been possible without SecDef Carter.

If I were to channel SecDef Carter, I believe he would emphasize three key actions:

1. Acknowledge and support those who serve in uniform, recognizing that their families also serve. We must ensure the well-being of all.
2. Understand that public service is a noble calling. If you have the chance to serve, take it.
3. Dedicate time to mentor someone or help open doors for those who lack the opportunities you have.

Thank you, Sir. It has been an extraordinary honor to serve alongside you.