Pentagon force planning is a dense and complicated blend of assumptions and projections, but operational scenarios are its most impactful ingredient. Their importance varies as administrations change and threats come and go, but depictions of the situations U.S. military forces and systems need to address are essential to setting investment priorities. Unfortunately, organizational inertia and a desire to compete for dollars lead U.S. military services to plan for scenarios that privilege their largest existing programs–even as America’s adversaries are moving on to an entirely different type of warfare.