Great power competition has returned after a generation of absence, and the U.S. military edge over prospective opponents is eroding. Whereas the United States previously could overwhelm adversaries with sheer force, if necessary, it now needs every advantage it can get. This study analyzes how the United States might inflict surprise on its adversaries to gain a strategic advantage. Surprise is one aspect of a broader discussion in the national security literature on innovative operational concepts, which may serve as force multipliers to enable the United States to get more out of existing capabilities. A follow up to CSIS's highly successful 2018 study Coping with Surprise in Great Power Conflicts, this report highlights several components of a successful surprise, including exploiting adversary vulnerabilities, using intelligence and technology, employing secrecy and deception, and doing the unexpected. The report also contains over a dozen vignettes illustrating potential future surprises.

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.

This study identifies five alternative strategies and, using CSIS's Force Cost Calculator, builds a cost-capped force structure, modernization program, and readiness profile for each strategy. It then stress-tests each strategy against four sets of simultaneous conflict scenarios, which the authors devised. The study explores potential ways to mitigate the fiscal pressure forcing these strategic tradeoffs. It concludes by making recommendations for the FY 2017 defense budget and the next Quadrennial Defense Review (QDR).