The US military needs to adapt to modern warfare

The conflict in Iran has put a spotlight on the vulnerabilities of fossil fuels. Over the last few weeks, we’ve watched the Strait of Hormuz close, cutting off 20% of the world’s oil supply and resulting in a 55% jump in oil prices. Every industry is feeling the impact of this. But no sector is more exposed than defense.

The U.S. military is the largest single institutional consumer of oil on the planet, and right now, that’s a strategic problem.

Modern warfare is increasingly fought by small, agile teams using robotics and autonomous systems on discrete, short-duration missions.

Estimates report that the United States armed forces consume approximately 4.6 billion gallons of fuel per year. If the Pentagon were a country, it would rank among the top 60 oil-consuming nations on earth. That demand doesn’t pause during a geopolitical crisis.

What the Hormuz disruption exposed is a fundamental issue: The machines that project force are the same machines most vulnerable to fuel supply disruption.

The true cost of a gallon

The cost of military fuel is much deeper than a dollar amount. Defense logistics professionals use a metric called the fully burdened cost of fuel, which accounts for procuring, transporting, and protecting a gallon of petroleum from the point of purchase to the point of use.

In some cases, the cost has been reported as high as $1,000 per gallon when shipping to the theater of war in the Middle East. In future major contested conflicts (particularly in the Pacific), fuel logistics could be pushed to the breaking point, with the challenges far greater than those faced in Iraq and Afghanistan.

We aren’t just paying for fuel in dollars. Fuel convoys cost lives. According to an Army Environmental Policy Institute study, U.S. forces sustained one casualty for every 24 fuel and water resupply convoys in Afghanistan. Between 2003 and 2007, an estimated 3,000 American soldiers and contractors were killed or wounded in attacks on fuel and water convoys.

The reason those convoys were so frequent comes down to raw consumption. A large Army division may use up to 6,000 gallons of fuel per day. The M1 Abrams tank gets less than 0.6 miles per gallon. The Army’s generator fleet, which powers lighting, communications, and base operations at forward locations, consumed approximately 357 million gallons per year during peak wartime operations in Iraq and Afghanistan.

Rethinking energy at the edge

Addressing this challenge requires rethinking not just how energy is sourced, but how much of it we need in the first place, where it’s going, and what we’re using.

The U.S. military spent an estimated $20.2 billion annually on air conditioning structures in Iraq and Afghanistan, making heating and cooling one of the largest energy expenses on a forward operating base. Simple interventions like spray foam insulation can cut climate-control costs by 50%, according to Army research at the National Training Center. Less demand means fewer convoys, fewer casualties, and greater operational freedom.

Modern warfare is increasingly fought by small, agile teams using robotics and autonomous systems on discrete, short-duration missions. Military logistics are evolving to match, minimizing the need to resupply fuel to smaller, distributed bases.

On the supply side, the answer isn’t a single alternative fuel. It’s an all-inclusive energy strategy: small-scale nuclear, solar paired with battery storage, hydrogen, wind, and hybridized fossil fuel generators working in concert.

Some real-life examples of this strategy include:

• Nuclear microreactors as part of the Pentagon’s Project Pele have demonstrated that a reactor powerful enough to run a forward operating base can be packaged into standard shipping containers and airlifted by a C-17.
• Solar power and hydrogen allowed the U.S. Army Corps of Engineers to run 24/7 perimeter security and surveillance at the White Sands Missile Range, completely unmanned, with zero power outages for 13 months.
• The Air Force has certified biofuel blends across its fleet. And companies like AirCo are using captured CO2 and hydrogen to create synthetic fuels, earning them a $65 million contract with the Department of War.

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Sebnem Coskun/Anadolu/Getty Images

From logistics to resilience

Reducing fuel dependence improves force protection by minimizing resupply missions. It increases operational flexibility by allowing units to operate independently of fixed supply lines.

A 2023 U.S. Naval Institute Proceedings article warned that in a future Pacific conflict, the entire fuel logistics chain would be exposed to attack at every point, making energy resilience a priority the military cannot afford to delay.

Energy resilience also supports the realities of modern warfare. Future conflicts will be increasingly unmanned and robotic. Autonomous systems, persistent surveillance, and distributed command-and-control networks all require reliable, long-duration power.

Modern conflicts are more distributed, which means supply chains are more contested. The solution is not to find a single replacement fuel, but to build an energy strategy that is diverse by design while simultaneously reducing energy demand through better insulation, smarter base design, and leaner logistics.

The goal is an energy posture resilient enough that no single choke point — not the Strait of Hormuz, not a convoy ambush, not a supply line disruption — can degrade our ability to operate.

The question is no longer whether alternatives exist. It is whether we have the strategic will to build the energy architecture modern warfare demands.

This article was originally published by RealClearDefense and made available via RealClearWire.