Veterans know firsthand the dangerous challenges that come from fossil-fuel dependence, and many are choosing to help the country transition to a clean-energy economy when they return home.

As a veteran, I personally know the high price we pay in blood and resources to secure oil supplies, from protecting desert fuel convoys to keeping international shipping lanes open for oil tankers. The U.S. military is the largest national consumer of fossil fuels and is most vulnerable to global price shocks that cut into already shrinking budgets; this is why the Department of Defense is pushing to end its fossil fuel dependency. There’s even an upcoming documentary on the effort called The Burden (I’m an advisor on the film).

In 2004, I deployed as an Army captain to Baiji, Iraq, located just 155 miles north of Baghdad. The city is home to Iraq’s largest oil refinery, which accounted for more than a quarter of the country’s refining capacity. My tour in Iraq was served in the shadow of endless oil fires. From 2004 to 2007, the city was a known stronghold for Sunni militants who siphoned oil and petroleum products to finance their operations. Ten years later, it’s as though I am reliving history, as ISIS forces and the Iraqi Army continue to battle for control of the Baiji refinery.