Military–industrial complex
Etymology: U.S. President Dwight D. Eisenhower originally coined 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. We recognize the imperative need for this development. Yet we must not fail to comprehend its grave implications. Our toil, resources and livelihood are all involved; so is the very structure of our society.
In the councils of government, we must guard against the acquisition of unwarranted influence, whether sought or unsought, by the military–industrial complex. The potential for the disastrous rise of misplaced power exists, and will persist.

We must never let the weight of this combination endanger our liberties or democratic processes. We should take nothing for granted. Only an alert and knowledgeable citizenry can compel the proper meshing of the huge industrial and military machinery of defense with our peaceful methods and goals so that security and liberty may prosper together. [emphasis added]
The phrase was thought to have been "war-based" industrial complex before becoming "military" in later drafts of Eisenhower's speech, a claim passed on only by oral history. Geoffrey Perret, in his biography of Eisenhower, claims that, in one draft of the speech, the phrase was "military–industrial–congressional complex", indicating the essential role that the United States Congress plays in the propagation of the military industry, but the word "congressional" was dropped from the final version to appease the then-currently elected officials. James Ledbetter calls this a "stubborn misconception" not supported by any evidence; likewise a claim by Douglas Brinkley that it was originally "military–industrial–scientific complex". Additionally, Henry Giroux claims that it was originally "military–industrial–academic complex". The actual authors of the speech were Eisenhower's speechwriters Ralph E. Williams and Malcolm Moos.

The MIC and the Cold War: Attempts to conceptualize something similar to a modern "military–industrial complex" did exist before 1961, as the underlying phenomenon described by the term is generally agreed to have emerged during or shortly after World War II. For example, a similar phrase was used in a 1947 Foreign Affairs article in a sense close to that it would later acquire, and sociologist C. Wright Mills contended in his 1956 book The Power Elite that a democratically unaccountable class of military, business, and political leaders with convergent interests exercised the preponderance of power in the contemporary West. Some sociologists have also connected it to Harold Lasswell's concept of the "garrison state" and James Burnham's notion of the "managerial revolution."

However, following its coinage in Eisenhower's address, the MIC became a staple of American political and sociological discourse. Many Vietnam War–era activists and polemicists, such as Seymour Melman and Noam Chomsky employed the concept in their criticism of U.S. foreign policy, while other academics and policymakers found it to be a useful analytical framework. The MIC was often advanced as both a symptom and a cause of broader dynamics such as militarism, economic centralization, and the influence of the private sector over public policy. Writing in 1968, for example, one economist argued that, in the case of the MIC: Government not only permits and facilitates the entrenchment of private power but serves as its fountain-head. It creates and institutionalizes power concentrations which tend to breed on themselves and to defy public control... Lacking a network of government-owned arsenals, such as produced the shot and cannon in the days of American innocence, or having dismantled the arsenals it did have, the government is forced to buy what it no longer can make. It becomes a monopsonistic buyer of products which are not yet designed or for which production experience is lacking. It buys at prices for which there is little precedent and hardly any yardsticks. It deals with contractors, a large percentage of whose business is locked into supplying defense, space, or atomic energy needs. It confronts powerful oligopolists in a market where technical capability rather than price is the controlling variable in an atmosphere shrouded by multilateral uncertainty and constant warnings about imminent aggression. Although the MIC was bound up in its origins with the bipolar international environment of the Cold War, some contended that the MIC might endure under different geopolitical conditions (for example, George F. Kennan wrote in 1987 that "were the Soviet Union to sink tomorrow under the waters of the ocean, the American military–industrial complex would have to remain, substantially unchanged, until some other adversary could be invented."). The collapse of the USSR and the resultant decrease in global military spending (the so-called 'peace dividend') did in fact lead to decreases in defense industrial output and consolidation among major arms producers, although global expenditures rose again following the September 11 terror attacks and the ensuing global war on terror, as well as the more recent increase in geopolitical tensions associated with strategic competition between the United States, Russia, and China. Through to the present, the military-industrial complex has continued to be seen by many as an analytically sound and important concept.

Eras: Some sources divide the history of the military–industrial complex into three distinct eras.

First era: From 1797 to 1941, the government only relied on civilian industries while the country was actually at war. The government owned their own shipyards and weapons manufacturing facilities which they relied on through World War I. With World War II came a massive shift in the way that the U.S. government armed the military.
With the onset of World War II President Franklin D. Roosevelt established the War Production Board to coordinate civilian industries and shift them into wartime production. Throughout World War II arms production in the United States went from around one percent of annual GDP to 40 percent of GDP. Various U.S. companies, such as Boeing and General Motors, maintained and expanded their defense divisions. These companies have gone on to develop various technologies that have improved civilian life as well, such as night-vision goggles and GPS.

Second era: The second era is identified as beginning with the coining of the term by President Dwight D. Eisenhower. This era continued through the Cold War period, up to the end of the Warsaw Pact and the collapse of the Soviet Union. A 1965 article written by Marc Pilisuk and Thomas Hayden says benefits of the military–industrial complex of the United States include the advancement of the civilian technology market as civilian companies benefit from innovations from the MIC and vice versa. In 1993, the Pentagon urged defense contractors to consolidate due to the fall of communism and a shrinking defense budget.

Third (current) era: In the third era, defense contractors either consolidated or shifted their focus to civilian innovation. From 1992 to 1997 there was a total of US$55 billion worth of mergers in the defense industry, with major defense companies purchasing smaller competitors.
The U.S. domestic economy is now tied directly to the success of the MIC which has led to concerns of repression as Cold War-era attitudes are still prevalent among the American public.
Shifts in values and the collapse of communism have ushered in a new era for the military–industrial complex. The Department of Defense works in coordination with traditional military–industrial complex aligned companies such as Lockheed Martin and Northrop Grumman. Many former defense contractors have shifted operations to the civilian market and sold off their defense departments.

Military subsidy theory: According to the military subsidy theory, the Cold War–era mass production of aircraft benefited the civilian aircraft industry. The theory asserts that the technologies developed during the Cold War along with the financial backing of the military led to the dominance of U.S. aviation companies. There is also strong evidence that the United States federal government intentionally paid a higher price for these innovations to serve as a subsidy for civilian aircraft advancement.

Current applications: According to the Stockholm International Peace Research Institute (SIPRI), total world spending on military expenses in 2022 was $2,240 billion. 39% of this total, or $837 billion, was spent by the United States. China was the second largest spender, with $292 billion and 13% of the global share. The privatization of the production and invention of military technology also leads to a complicated relationship with significant research and development of many technologies. In 2011, the United States spent more (in absolute numbers) on its military than the next 13 countries combined.
The military budget of the United States for the 2009 fiscal year was $515.4 billion. Adding emergency discretionary spending and supplemental spending brings the sum to $651.2 billion. This does not include many military-related items that are outside of the Defense Department's budget. Overall, the U.S. federal government is spending about $1 trillion annually on military-related purposes.
President Joe Biden signed a record $886 billion defense spending bill into law on December 22, 2023.
In a 2012 story, Salon reported, "Despite a decline in global arms sales in 2010 due to recessionary pressures, the United States increased its market share, accounting for a whopping 53 percent of the trade that year.