This report seeks to inform the debate over the extent of U.S. military presence overseas by providing a rigorous estimate of the costs associated with maintaining U.S. Air Force installations and units overseas rather than in the United States. The authors describe the various types of expenditures required to maintain bases and military units overseas and estimate current costs using official data and econometric modeling. They provide a cost model of overseas presence for policymakers to weigh alternative posture options. Their main findings are that while it does cost more to maintain force structures and installations overseas rather than in the United States, the total cost of doing so for the Air Force's current overseas posture is small relative to the Air Force's overall budget.

This report seeks to inform the debate over the extent of U.S. military presence overseas by providing a rigorous estimate of the costs associated with maintaining U.S. Air Force installations and units overseas rather than in the United States.

This independent assessment is a comprehensive study of the strategic benefits, risks, and costs of U.S. military presence overseas. The report provides policymakers a way to evaluate the range of strategic benefits and costs that follow from revising the U.S. overseas military presence by characterizing how this presence contributes to assurance, deterrence, responsiveness, and security cooperation goals.

This independent assessment is a comprehensive study of the strategic benefits, risks, and costs of U.S. military presence overseas. The report provides policymakers a way to evaluate the range of strategic benefits and costs that follow from revising the U.S. overseas military presence by characterizing how this presence contributes to assurance, deterrence, responsiveness, and security cooperation goals.

U.S. Air Force (USAF) global posture—its overseas forces, facilities, and arrangements with partner nations—faces a variety of fiscal, political, and military challenges. This report seeks to identify why the USAF needs a global posture, where it needs basing and access, the types of security partnerships that minimize peacetime access risk, and the amount of forward presence that the USAF requires.

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.

There are growing calls for a decrease in the U.S. military presence in the Middle East. This CSIS report assesses three posture options for U.S. forces in the region to inform the debate over the United States' military presence in the Middle East. The report finds that the United States should keep a notable but tailored presence in the Middle East to contain the further expansion of Chinese and Russian military power and to check the actions of Iran and terrorist organizations that threaten the United States and its allies and partners.