The Homeland Security Operational Analysis Center (HSOAC), a U.S. Department of Homeland Security (DHS) federally funded research and development center (FFRDC) operated by the RAND Corporation, was commissioned to generate a report on the Arctic capabilities of the U.S. armed forces, as directed in Section 8424 of the National Defense Authorization Act (NDAA) for Fiscal Year 2021. This report documents the U.S. armed forces' current and planned Arctic capabilities, as well as other nations'-allies', other partners', and potential rivals'-operating capabilities in the Arctic. We evaluated limitations to U.S. access and presence, including issues related to domain awareness and communications. We also considered how cooperation with federal, international, and commercial entities affects the ability to execute national security missions and priorities where access and presence are a means for doing so.The research was conducted using a mixed-method approach that relied on interviews, capability documentation, computer simulation and data analysis, logic modeling, and a tabletop exercise. The scope was broad in terms of mission and domain, although, in accordance with the fiscal year 2021 NDAA and research sponsor interests, some aspects of this report emphasize the surface maritime domain and U.S. Coast Guard (USCG) statutory missions, including defense readiness; ice operations; ports, waterways, and coastal security; search and rescue; law enforcement; and marine environmental protection response activities. The report's expansion beyond the scope requirements of the original NDAA is based on the need to analyze additional areas to address those that were explicitly stated in the NDAA.This research is intended to inform the U.S. Congress and support continued Arctic planning and investments by the USCG and other U.S. armed forces. Information found in this report was current as of May 2022. We acknowledge that the ongoing war in Ukraine at the time of this writing could influence Arctic issues.This research was sponsored by the USCG Office of Requirements and Analysis (CG-771) and conducted in the Infrastructure, Immigration, and Security Operations Program of the RAND Homeland Security Research Division, which operates HSOAC.