U.S. Role in the World: Background and Issues for Congress [Updated November 18, 2019] [open pdf - 1MB]
From the Introduction: "This report provides background information and issues for Congress regarding the U.S. role in the world, meaning the overall character, purpose, or direction of U.S. participation in international affairs and the country's overall relationship to the rest of the world. The U.S. role in the world can be viewed as establishing the overall context or framework for U.S. policymakers for developing, implementing, and measuring the success of U.S. policies and actions on specific international issues, and for foreign countries or other observers for interpreting and understanding U.S. actions on the world stage."
CRS Report for Congress, R44891
Congressional Research Service: https://crsreports.congress.gov/