The expression military–industrial complex (MIC) describes the relationship between a country's military and the defense industry that supplies it, seen together as a vested interest which influences public policy. A driving factor behind the relationship between the military and the defense-minded corporations is that both sides benefit—one side from obtaining war weapons, and the other from being paid to supply them. The term is most often used in reference to the system behind the armed forces of the United States, where the relationship is most prevalent due to close links among defense contractors, the Pentagon, and politicians. The expression gained popularity after a warning of the relationship's detrimental effects, in the farewell address of President Dwight D. Eisenhower on January 17, 1961.
In the context of the United States, the appellation is sometimes extended to military–industrial–congressional complex (MICC), adding the U.S. Congress to form a three-sided relationship termed an "iron triangle". Its three legs include political contributions, political approval for military spending, lobbying to support bureaucracies, and oversight of the industry; or more broadly, the entire network of contracts and flows of money and resources among individuals as well as corporations and institutions of the defense contractors, private military contractors, the Pentagon, Congress, and the executive branch.
President of the United States (and five-star general since World War II) Dwight D. Eisenhower used the term in his Farewell Address to the Nation on January 17, 1961:
A vital element in keeping the peace is our military establishment. Our arms must be mighty, ready for instant action, so that no potential aggressor may be tempted to risk his own destruction...
This conjunction of an immense military establishment and a large arms industry is new in the American experience. The total influence—economic, political, even spiritual—is felt in every city, every statehouse, every office of the federal government.