From the Document: "Electronic warfare (EW), as defined by the Department of Defense (DOD), are military activities that use electromagnetic energy to control the electromagnetic spectrum ('the spectrum') and attack an enemy. The spectrum is a range of frequencies for electromagnetic energy. EW supports command and control (C2) by allowing military commanders' access to the spectrum to communicate with forces, while preventing potential adversaries from accessing the spectrumto develop an operational picture and communicate with their forces. Some have argued that EW is a component of anti-access/area denial (A2/AD) campaigns. [...] The National Defense Strategy, released in 2018, emphasized the return of great-power competition, reflecting China's and Russia's ongoing efforts to modernize their forces to counter U.S. military advantages. In addition, the congressionally mandated National Defense Strategy Commission, which independently evaluated DOD strategy, stated that the United States is losing its advantages in electronic warfare, hindering the nation's ability to conduct military operations against capable adversaries. The commission recommended increasing EW investments and developing new concepts to regain U.S. military advantage. Each service has incorporated EW capabilities into platforms and combat systems and is currently working to modernize its existing capabilities."
CRS In Focus, IF11118
Congressional Research Service: https://crsreports.congress.gov/