The U.S.' top general reflects on the changing face of war, 79 years after D-Day

President Biden's top military adviser says the U.S. has resolved that people — not computers — should continue making life-or-death decisions in war.

Responding to widespread concerns about the power of artificial intelligence, Gen. Mark Milley said U.S. policy — unlike that of some "adversarial countries" — is "to ensure that humans remain in the decision-making loop."

The chairman of the Joint Chiefs of Staff reflected on the changing nature of warfare in an interview with Morning Edition on the eve of the 79th anniversary of D-Day, when thousands of U.S. and allied forces stormed the beaches of Normandy to begin the liberation of Western Europe from Nazi Germany.

Milley was among the U.S. officials, World War II veterans and other visitors who visited Normandy to mark the anniversary and honor those who served.

It's a significant trip for Milley in part because it's his last: He plans to retire when his tenure ends in September — after more than four decades of service in multiple command and staff positions in eight divisions and Special Forces.

Milley, the son of WWII veterans, says defending the principles of the Constitution has been a driving force throughout his life.

"That was the gift my parents gave to me from World War II," he says. "That's the gift of all these veterans on these beaches that we're meeting around here. And I think that's my one obligation to pass that on to the next generation and beyond."

On Friday, France's president awarded Milley the country's highest medal of honor for his more than 40-year military career "spent in defense of democracy," including his role coordinating support for Ukraine.

Tuesday's anniversary comes at a pivotal moment for Ukraine, which appears to be launching its long-awaited counteroffensive against Russia (there is speculation that it has started in recent days, though Kyiv says there will be no formal announcement). The U.S. is among the allies that have continued to arm Ukraine with military aid, including advanced fighter jets, for this purpose.

Milley says there are fundamental lessons of warfare that apply in this latest European battlefield. At the same time, he adds, new technology has brought about a major change in the character of war for the first time in decades, with implications for the U.S.

"We've got to make sure we modernize our military so that we remain dominant," he says. "And by doing that [we] will deter any sort of potential aggression by any future great power that might threaten the United States and our interests."

Milley spoke to Morning Edition's Steve Inskeep about lessons from the past — from an ancient Greek historian to his own family's sacrifices — and possible threats of the future.

This interview has been edited and condensed for clarity.

Interview highlights

On the fundamentals of warfare that still apply today

If you look back at the ancients, you look at [ancient Greek military historian] Thucydides for example, and he tells us that the cause of war is primarily fear, interest and pride. I think all three of those are clearly at play here in many, many ways with respect to Russia. Their pride was hurt significantly with the fall of the Berlin Wall and the movement of the NATO boundary from the inner-German border between East [and] West Germany and and then moving that NATO boundary further to the east. ... There's fear on both sides there, with Ukraine afraid of Russian and Russia's afraid of encroachment by NATO and being surrounded and their fear of threat to mother Russia. So all of those [are] still in play as there's a lot of lessons coming from the ancients.

On the technological advancements changing the face of war

The character of war fundamentally changes only once in a while ... and the last big one was between World War I and World War II with the introduction of mechanization, the airplane, the radio. But today we're undergoing a fundamental change in the character of war. What you see playing out in Ukraine, you're seeing snippets of that. You see urbanization of battle, you see the widespread use of precision munitions, you see the widespread use of electronic warfare, you see the widespread use of unmanned aerial vehicles, offset long-range precision fires, you see joint operations, you see all of that in small form somewhat in Ukraine. ... [The U.S. has] got to make sure that we maintain our edge, we maintain our readiness, and we modernize our force in the ways that are necessary for for the future operating environment, which is going to accentuate long-range precision fires, artificial intelligence, robotics, all of those sorts of things are going to be at play in the future.

On what artificial intelligence could mean for the battlefield

There's little doubt in my mind that artificial intelligence is going to play a fundamental and big role in future operations. ... Theoretically, it allows you to see the enemy and see yourself and process all the incredible amounts of information at a faster rate of speed than your adversary. And if you add quantum computing and artificial intelligence together, and then if you combine them with robotics, machines, then you get a degree of power and synergy that could change warfare in ways that we've absolutely never seen before. There's a lot of ethical issues here. There's a lot of legal issues. There's a lot of policy issues that will have to be resolved.

Whatever country it is that optimizes these capabilities ... the best for military operations is going to have a decisive advantage at the beginning of the next conflict. And I want that country to be the United States.

On how the U.S. approach to AI differs from other countries'

The nature of war is built upon the assumption that human beings are driving decision-making in the conduct of war ... The United States' policy right now, actually, with respect to artificial intelligence and its application to military operations, is to ensure that humans remain in the decision-making loop. That is not the policy necessarily of adversarial countries that are also developing artificial intelligence. ...

... As we develop these systems over time, we've got to really pay close attention to how they are developed. Another key thing to recall, too, is we've had various arms control measures in the past because of the potential power of some of these systems. There are potential opportunities here for international regimes that could put limits and mitigate the use of some of this stuff in terms of military operation, because these things are extremely powerful technologies and we have yet to realize how powerful they are. And we're just at the beginning of this. So a lot of thought, a lot of very considered analytical work is going to have to be done for all the countries of the world to come to grips with these capabilities.

The broadcast interview was produced by Nina Kravinsky and Barry Gordemer, and edited by Mohamad ElBardicy.