Electromagnetic Spectrum Operations: DOD Needs to Address Governance and Oversight Issues to Help Ensure Superiority, Report to the Committee on Armed Services, House of Representatives [open pdf - 2MB]
From the Highlights: "According to DOD, the EMS [electromagnetic spectrum] is essential for facilitating control in operational environments and impacts operations in the air, land, sea, space, and cyber domains. The pervasiveness of the EMS across warfighting domains means that maintaining or achieving EMS superiority against an adversary is critical to battlefield success. House Report 116-120 that accompanied a bill for the National Defense Authorization Act for Fiscal Year 2020 included a provision that GAO [Government Accountability Office] assess DOD's EMS strategy. This report (1) describes reported threats from peer adversaries; (2) outlines challenges to DOD's superiority in the EMS; and (3) evaluates the extent to which DOD has implemented EMS-related strategies and is positioned to achieve future goals."
Government Accountability Office: https://www.gao.gov/