Over the past decade, the size of the U.S. military has fallen to historic lows in the post-World War II era by almost all measures. Active-duty end strength peaked in Fiscal Year 1952, during the Korean War, at 3.6 million servicemembers. Yet by FY2020, that figure had declined by over 60 percent, driven in part by significant post-Cold War reductions in the 1990s. This trend poses a key question: Can the Department of Defense afford a military force of sufficient size to support the country’s defense strategy in the coming years and decades? The answer hinges, in part, on whether it can manage the growth of military personnel costs, which have more than doubled between FY1952 and FY2020 when adjusted for inflation.