Retired U.S. Army Lieutenant General Mark Hertling, whose 37-year military career included serving as Commanding General for United States Army Europe, published an essay in The Bulwark on Wednesday warning the Trump administration against confusing confidence with strategic clarity. His central message: "never underestimate your enemy."

Hertling drew the lesson from his own experience. During a deployment in Iraq two decades ago, militia leader Muqtada al-Sadr managed to rebuild his forces even after absorbing what Hertling described as "enormous damage" from U.S. military operations. That experience, he wrote, taught him that "tactical success does not automatically become strategic victory, and destroying enemy formations is not the same as destroying an enemy's will or capacity to continue fighting" — a principle he argued the current Pentagon leadership appears to disregard.

The retired general's critique was prompted by Defense Secretary Pete Hegseth's testimony before the Senate Appropriations Committee. During questioning about the operation in Iran, Hegseth characterized the country's "Revolutionary Guard as effectively defeated and destroyed" and called the American campaign "a decisive success." The Islamic Revolutionary Guard Corps, designated by the United States as a foreign terrorist organization in 2019, functions not only as Iran's primary military striking force but also as a sprawling political and economic institution deeply embedded in the Iranian state.

Hertling pushed back on that assessment. "As I watched Secretary of Defense Pete Hegseth testify before the Senate Appropriations Committee yesterday, I couldn't help thinking about a tour in Iraq twenty years ago," he wrote. "That was where I was taught a lesson that every soldier eventually learns, usually the hard way: never underestimate your enemy. Confidence is essential in combat, but swagger is dangerous because it tempts leaders into believing they already know what will happen, or how a battle or war will end. The enemy always gets a vote." The Bulwark, where Hertling published his essay, is a news and opinion outlet founded by conservative commentators who have been critical of Trump and has become a prominent platform for national-security and defense analysis from figures across the political spectrum.

Despite the administration's declarations of success, Hertling observed that "Iran remains capable of conducting military operations, threatening maritime traffic, and imposing costs on American forces," adding that "the war continues to rage unabated." His warning echoes a long-standing tension in American military history, from the Vietnam-era gap between battlefield metrics and strategic outcomes to the post-2003 Iraq insurgency, where declared major combat operations were followed by years of sustained resistance.

"Swagger may energize political supporters and produce memorable television clips, but it is not strategy," Hertling concluded. "Strategy begins with a clear understanding of the enemy, realistic assessments of what military force can accomplish, and enough humility to recognize that wars rarely unfold according to plan. More than two decades after learning that lesson in southern Iraq, I still remind myself never to predict the outcome of a war while the enemy is still fighting. Secretary Hegseth and President Trump would be well served to remember that lesson today."