Iran Has Shown Us What Modern War Looks Like

By Lloyd J. Austin III

Mr. Austin served as the secretary of defense from 2021 to 2025.

Throughout my 41 years in the United States Army and my four years as the secretary of defense, I routinely held after-action reviews. Our military never stops learning and never stops asking: What worked, what didn’t, and how do we get better? That ensures America’s military remains the best and deadliest fighting force in the world.

The U.S. military must also learn from the war with Iran, which is already one of the most consequential conflicts in decades. Although the strategic outcome is........

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