The Missile Defense Agency and U.S. Army issued this joint Record of Decision on September 9, 2025, selecting the Proposed Action to construct, deploy, operate, and maintain a comprehensive 360-degree Enhanced Integrated Air and Missile Defense (EIAMD) system across 16 sites on DoD lands on Guam. The EIS analyzed two alternatives: the Proposed Action and No Action. Significant impacts include loss of limestone forest and approximately 5,459 individuals of the ESA-listed plant Cycas micronesica, major effects on the ESA-listed Mariana fruit bat, and long-term major impacts on Guam's housing, health care, and traffic. Mitigations include habitat enhancement sites, plant salvage and transplantation, and phased personnel deployment. The No Action Alternative was identified as environmentally preferred but rejected as inconsistent with the congressional mandate for persistent air and missile defense of Guam.1