Information Operations is a category of direct and indirect support operations for the United States Military. By definition in Joint Publication 3-13, "IO are described as the integrated employment of electronic warfare (EW), computer network operations (CNO), psychological operations (PSYOP), military deception (MILDEC), and operations security (OPSEC), in concert with specified supporting and related capabilities, to Information Operations (IO) are actions taken to affect adversary information and information systems while defending one's own information and information systems.

The modern U.S. military can trace its use of information operations back to World War 2 when the Army activated the 23rd Headquarters Special Troops, known as the "Ghost Army", on January 20, 1944. This secretive unit was responsible for executing 22 large-scale military deceptions in Europe using techniques such as inflatable vehicles, false radio transmissions, loud-speaker sound effects, and phony generals. Specific operations the 23rd was noted for having success was D-Day and Operation Viersen. Today the 23rd, has been attributed as saving the lives of 15,000 to 30,000 American service members. In the Pacific, the Navy successfully conducted its first electronic warfare activities later in the war when TBM Avenger aircraft were fitted with receivers and rudimentary jammers to locate and jam Japanese air search radars.

Despite the success of the 23rd, deception was never used in a significant way in Korean War, however psychological warfare was routinely conducted by the Eighth Army, predominantly in the form of airborne leaflets, including a weekly "news" leaflet dropped on communist forces, but also included radio and loudspeaker broadcasts. During the war forces under United Nations Command used electronic jamming, much like the Navy at the end of World War 2, against radar on radar-directed anti-aircraft guns, particularly during Operation Strangle. Though these examples fall within the capabilities associated with information operations, they were applied in specific circumstances for particular missions and not de-conflicted or synchronized for maximum effect. Because of their discrete applications, information operations was not fully exercised during the war as it is known today.

Much the same as in the Korean War, deception was also disregarded as a practice during the Vietnam War.

In the mid-1990s, the U.S. Department of Defense began characterizing doctrine known as Command and Control Warfare (C2W) which was described as a strategy to attack the decision-making, or command and control (C2) capabilities of an adversary while protecting the decision-making capabilities of friendly forces. It focused on a robust targeting system and defined five core capabilities, called pillars, it leverages: operations security, military deception, psychological operations, electronic warfare, and physical destruction.

On December 9, 1996, the Deputy Secretary of Defense, John P. White approved the Department of Defense release of a then Secret Directive S-3600.1 that codified the concept of Information Operations. This directive mandated the U.S. Armed Services to develop their own doctrine, training, and equipment, to execute information operations.

Shortly after the release of DODD S-3600.1, the U.S. Army stood up the Land Information Warfare Activity/Information Dominance Center (LIWA/IDC), which would eventually transition into the 1st Information Operations Command (Land), and established the Information Operations functional area in April 1999 to specially train and assign commissioned officers to plan and conduct IO.

During this time, the Army National Guard began to engage in developing their own information operations capabilities, establishing ad hoc information operations field support teams (FSTs), and vulnerability assessments teams (VATs), coordinated with the LIWA/IDC. National Guard units from Washington, Iowa, Vermont, and Texas were part of this early development.