When Russia Invaded Ukraine in February 2022 Ukraine’s military was only a few years out of a complete reorganization. Many analysts focus on the training, advice, and support it had received on offensive and defensive operations, its professional military education reforms, or its emphasis on employing new Western weapons like Javelins. And yet it is often the seemingly more peripheral factors that limit—or enhance—a military’s battlefield prospects. Military leaders from Frederick the Great to Napoleon knew more than two centuries ago that an army marches on its stomach, and yet most observers paid scant attention to this element of Ukraine’s defense. Even with the best weapons, the best training, and the best leadership, an armed force can only fight as long as it is fed. One person who has lived that truism every day in Ukraine for the past fourteen months is Chef Zhenya Mykhailenko.

Chef Zhenya, also known as the Soup Daddy on social media, is a famous Ukrainian chef. He has trained in culinary arts around the world. He owns no fewer than seven restaurants in Kyiv and has inspired countless others across Ukraine and beyond. I met him last month in a very dark bar only accessible through an unmarked black door, a scene more reminiscent of a John Wick movie than the middle-class neighborhood in Ukraine’s capital where it sits.

Chef Zhenya greeted me with a smile and a firm handshake. The chef is an imposing figure, a sizeable man covered in tattoos, most of which depict various cooking utensils, measurement conversion charts, or other symbols of his profession.

When Russian forces began their weeks-long attempt to capture Kyiv on February 24, 2022, Chef Zhenya answered the call to serve like tens of thousands of other Ukrainians in the city. But instead of being handed a rifle, Chef Zhenya was given a massive kitchen near the country’s primary military headquarters where he immediately started preparing food for thousands of Kyiv’s defenders.

My initial questions for Chef Zhenya reflected my research interests as a student of urban warfare in general and the Battle of Kyiv in particular. How were tens of thousands of civilians and defenders fed and kept alive in a city under attack by the world’s second-most powerful military? Where? With what? How long could the city have survived if it had been besieged?

Chef Zhenya described being moved to a nongovernment building in a secret location during the first days of the war. Most of the military had moved out of their primary locations in case the Russians bombed known command centers or military installations.

I asked if he had been concerned that there was not enough food available. The question almost seemed unimportant to Chef Zhenya. With a preinvasion population of almost three million, Kyiv had no shortage of food supplies on hand. He had access to massive stockpiles of both perishable and nonperishable food in warehouses across the city. He quickly organized convoys of vans to move supplies to his own and other restaurant freezers. “I could have made porridge for a year,” he told me. But he didn’t want to. He cooked all day and night.

Restaurants were not open, but with their preexisting food supplies they were still cooking. They were sending everything they could out to the outlying defenders and civilians trapped across the city—like the thousands of civilians that were trapped underground when a three-day-long curfew was put in place.

The stories Chef Zenya told me about the Battle of Kyiv are fascinating in their own right. But on another level, they hold important clues to understanding something often not even discussed in war planning, particularly in an increasingly urbanized world. When war comes to a city, who will care for the millions of people trapped there? How prepared must civil society and administrators be? In caring for potentially millions of civilians, what will the military be asked to do while also fighting the enemy?

Chef Zhenya, as just a motivated private citizen, was vital to feeding the defenders of Kyiv. But he did not stop feeding soldiers when the Russians were completely defeated in the region around the capital on April 2, some five weeks after the invasion began. He still feeds thousands of soldiers a day, including on the front lines in places that have become well known around the world for the intensity of the fighting there—places like Kherson, Dnipro, and Zaporizhzhya. But what equally fascinated me was the work Chef Zhenya is doing to reform how the entire Ukrainian military feeds itself.

A Western military might take for granted the organizational systems and practices established to feed soldiers. But Chef Zhenya explained how everything from Soviet industrialization to military ignorance to cultural factors has slowed the Ukrainian military from being able to feed itself.

The “Soviet way,” according to Chef Zhenya, caused every facet of Ukrainian society to be industrialized into assembly lines. That included food production. No longer did bakers bake bread, for example. It was produced in bread factories. This led to an erosion of cooking traditions and left an inadequate portion of society capable of food preparation and cooking, something reflected in the Ukrainian military where even today there is no military occupational pipeline to create cooks.

The reforms Chef Zhenya is trying to make happen are many. The Ukrainian military lacks basic field food preparation and service capability. Having the knowledge to cook safe and nutritious food is one thing, but that can’t even begin if military units don’t have the basic supplies and tools to cook. Chef Zhenya showed me videos of soldiers hacking at frozen meat with hatchets and of meat left on the ground in the open air as soldiers tried to thaw their government-issued supplies.

Chef Zhenya conducts fundraisers and works with nonprofit organizations to bring soldiers food. He is also working to get military units tools such as mobile kitchen trailers and stockpiles of MREs (meals, ready-to-eat).

The thing that seemed to energize Chef Zhenya the most was field sanitation. With up to 80 percent of casualties among military personnel historically attributed to disease and nonbattle injuries such as diarrhea and dysentery, it is no wonder he is so passionate. These casualties sap operational strength and have a real impact on the battlefield. He described his anger when he visited units on the front lines and saw dogs in kitchens, dirty cooking utensils, food left out and unprotected, and a general ignorance of basic hygiene and sanitation practices.

Finally, it is not just the mechanics of ensuring soldiers are fed that are important, but also what they are eating. Chef Zhenya described finding many soldiers trying to survive their tours at the front eating energy drinks and candy bars because they feared getting sick from eating any food offered by their units.

Without a stable diet, the effects of combat are magnified. It is well known that nutrition, sleep, and physical activity are the keys to performance. Nutrition impacts not just soldiers’ physical ability to perform on the battlefield, but also their mental and emotional resilience. Ukraine needs healthy soldiers to achieve an ultimate victory over the Russian invaders.

The lessons from the Battle of Kyiv and the broader war in Ukraine are many. There has been no conflict in over seventy years that has more clearly exposed the most important factors of fighting a high-intensity war against a peer enemy in the most likely environment—urban terrain. The US military should study and implement changes based on a wide range of lessons, including the most effective use of combined arms formations, high ammunition expenditures, and the general complexity of urban warfare. But it should also learn lessons from leaders like Chef Zenya on subjects that typically garner less attention, if any at all—most fundamentally, that it is vital to have a plan to keep not just militaries fed, but also partner forces and urban populations. It is true that an army marches on its stomach, but it also only survives on adequate, clean, balanced food supplies.

John Spencer is the chair of urban warfare studies at the Modern War Institute at West Point. He recently returned from Ukraine where he was researching the 2022 Battle of Kyiv. He is author of Connected Soldier: Life, Leadership, and Social Connections and Understanding Urban Warfare. You can connect with him @SpencerGuard. Chef Zhenya Mykhailenko can be found @chefzhenya.

The views expressed are those of the author and do not reflect the official position of the United States Military Academy, Department of the Army, or Department of Defense.