Suppression of Enemy Air Defenses (SEAD), also known as "Wild Weasel" and "Iron Hand" operations in the United States, are military actions to suppress enemy surface-based air defenses, including not only surface-to-air missiles (SAMs) and anti-aircraft artillery (AAA) but also interrelated systems such as early-warning radar and command, control and communication (C3) functions, while also marking other targets to be destroyed by an air strike. Suppression can be accomplished both by physically destroying the systems or by disrupting and deceiving them through electronic warfare. In modern warfare SEAD missions can constitute as much as 30% of all sorties launched in the first week of combat and continue at a reduced rate through the rest of a campaign. One quarter of American combat sorties in recent conflicts have been SEAD missions.
Prior to the Vietnam War, SEAD was an undefined mission: although attempts to destroy enemy air defense sites were undertaken, they were done so on an individual aircraft basis and in relation to specific targets or operations rather than as part of an overall strategy or doctrine of defense suppression. While crude, these tactics were effective for their time.
During the Battle of Britain, the German Luftwaffe attempted to destroy Great Britain's Chain Home radar stations in order to degrade the British air defense network. However, German High Command failed to realize the efficiency of not only the radar stations themselves but the command and control system directing Britain's air defenses. After initial optimism regarding the radar sites' destruction, it was eventually decided to halt these attacks altogether except for exceptional circumstances. As the air war in Europe shifted in favor of the Allies, the Germans relied heavily on their AAA to defend against bombing attacks. This was borne out in Allied aircraft losses between 1943 and 1944, where losses to enemy fighters was cut in half but losses to flak increased tenfold.