Electromagnetic warfare or electronic warfare (EW) is warfare involving the use of the electromagnetic spectrum or directed energy to control the spectrum, attack an enemy, or impede enemy operations. The purpose of electromagnetic warfare is to deny the opponent the advantage of—and ensure friendly unimpeded access to—the EM spectrum. Electromagnetic warfare can be applied from air, sea, land, or space by crewed and uncrewed systems and can target communication, radar, or other military and civilian assets.