CSIS's Mark Cancian annually produces a series of white papers on U.S. military forces, including their composition, new initiatives, long-term trends, and challenges. This report is a compilation of these papers. It takes a deep look at each military service, as well as special operations forces, DOD civilians, and contractors in the FY 2022 budget. The report also discusses the debate about legacy equipment, the interaction of the budget and force size, and the decline in force size that the services face with retiring older systems without adequate replacements.