Book excerpt: CSIS senior adviser 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 and takes a deep look at each of the military services, the new Space Force, special operations forces, DOD civilians, and contractors in the FY 2021 budget. This report further includes a foreword regarding how the Biden administration might approach decisions facing the military forces, drawing on insights from the individual chapters.