War is an armed conflict between the armed forces of states, or between governmental forces and armed groups that are organized under a certain command structure and have the capacity to sustain military operations, or between such organized groups. It is generally characterized by extreme violence, destruction, and mortality, using regular or irregular military forces. Warfare refers to the common activities and characteristics of types of war, or of wars in general. Total war is warfare that is not restricted to purely legitimate military targets, and can result in massive civilian or other non-combatant suffering and casualties.
The military history of the United States spans over two centuries, the entire history of the United States. During those centuries, the United States evolved from a newly formed nation which fought for its independence from the Kingdom of Great Britain (1775–1783) to world superpower status in the aftermath of World War II to the present. As of 2024, the United States Armed Forces consists of the Army, Marine Corps, Navy, Air Force and Space Force, all under the command of the Department of Defense, and the Coast Guard, which is controlled by the Department of Homeland Security.
The military–industrial complex (MIC) is a phrase originally coined by U.S. President Dwight D. Eisenhower to describe the relationship between the military and the defense industry that supplies it with weapons, equipment, and services.
Brinkmanship or brinksmanship is the practice of trying to achieve an advantageous outcome by pushing dangerous events to the brink of active conflict. The maneuver of pushing a situation with the opponent to the brink succeeds by forcing the opponent to back down and make concessions rather than risk engaging in a conflict that would no longer be beneficial to either side. That might be achieved through diplomatic maneuvers, by creating the impression that one is willing to use extreme methods rather than concede. The tactic occurs in international politics, foreign policy, labor relations, contemporary military strategy, terrorism, and high-stakes litigation.
People's war or protracted people's war is a Maoist military strategy. First developed by the Chinese communist revolutionary leader Mao Zedong (1893–1976), the basic concept behind people's war is to maintain the support of the population and draw the enemy deep into the countryside where the population will bleed them dry through guerrilla warfare and eventually build up to mobile warfare. It was used by the Chinese communists against the Imperial Japanese Army in World War II, and by the Chinese Soviet Republic in the Chinese Civil War.
A low-intensity conflict (LIC) is a military conflict, usually localised, between two or more state or non-state groups which is below the intensity of conventional war. It involves the state's use of military forces applied selectively and with restraint to enforce compliance with its policies or objectives.
In political science, a proxy war is an armed conflict fought between two belligerents, wherein one belligerent is a non-state actor supported by an external third-party power. In the term proxy war, the non-state actor is the proxy, yet both belligerents in a proxy war can be considered proxies if both are receiving foreign military aid from a third party country. Acting either as a nation-state government or as a conventional force, a proxy belligerent acts in behalf of a third-party state sponsor. A proxy war is characterised by a direct, long-term, geopolitical relationship between the third-party sponsor states and their client states and non-state clients, thus the political sponsorship becomes military sponsorship when the third-party powers fund the soldiers and their matériel to equip the belligerent proxy-army to launch and fight and sustain a war to victory, and government power.
An insurgency is a violent, armed rebellion by small, lightly armed bands who practice guerrilla warfare against a larger authority. The key descriptive feature of insurgency is its asymmetric nature: small irregular forces face a large, well-equipped, regular military force state adversary. Due to this asymmetry, insurgents avoid large-scale direct battles, opting instead to blend in with the civilian population where they gradually expand territorial control and military forces. Insurgency frequently hinges on control of and collaboration with local populations.
In political science, rollback is the strategy of forcing a change in the major policies of a state, usually by replacing its ruling regime. It contrasts with containment, which means preventing the expansion of that state; and with détente, which means developing a working relationship with that state. Most of the discussions of rollback in the scholarly literature deal with United States foreign policy toward communist countries during the Cold War. The rollback strategy was tried and was not successful in Korea in 1950 and in Cuba in 1961, but it was successful in Grenada in 1983. The United States discussed the use of rollback during the East German uprising of 1953 and the Hungarian Revolution of 1956, which were ultimately crushed by the Soviet Army, but decided against it to avoid the risk of a major war.
Collective security is a multi-lateral security arrangement between states in which each state in the institution accepts that an attack on one state is the concern of all and merits a collective response to threats by all. Collective security was a key principle underpinning the League of Nations and the United Nations. Collective security is more ambitious than systems of alliance security or collective defense in that it seeks to encompass the totality of states within a region or indeed globally.
Modern warfare is warfare that diverges notably from previous military concepts, methods, and technology, emphasizing how combatants must modernize to preserve their battle worthiness. As such, it is an evolving subject, seen differently in different times and places. In its narrowest sense, it is merely a synonym for contemporary warfare.
Counterinsurgency is "the totality of actions aimed at defeating irregular forces". The Oxford English Dictionary defines counterinsurgency as any "military or political action taken against the activities of guerrillas or revolutionaries" and can be considered war by a state against a non-state adversary. Insurgency and counterinsurgency campaigns have been waged since ancient history. However, modern thinking on counterinsurgency was developed during decolonization.
In military science, force multiplication or a force multiplier is a factor or a combination of factors that gives personnel or weapons the ability to accomplish greater feats than without it. The expected size increase required to have the same effectiveness without that advantage is the multiplication factor. For example, if a technology like GPS enables a force to accomplish the same results as a force five times as large without GPS, then the multiplier is five. Such estimates are used to justify the investment for force multipliers.
James Clarke Chace was an American historian, writing on American diplomacy and statecraft. His books include the critically acclaimed Acheson: The Secretary of State Who Created the American World (1998), the definitive biography of former Secretary of State Dean Acheson. In a debate during the 2000 presidential primary, George W. Bush referred to Chace's Acheson as one of the books he was reading at the time.
The war on terror, officially the Global War on Terrorism (GWOT), is a global counterterrorist military campaign initiated by the United States following the September 11 attacks of 2001, and is the most recent global conflict spanning multiple wars. Some researchers and political scientists have argued that it replaced the Cold War.
Cost of Conflict is a tool which attempts to calculate the price of conflict to the human race. The idea is to examine this cost, not only in terms of the deaths and casualties and the economic costs borne by the people involved, but also the social, developmental, environmental and strategic costs of conflict. In most cases organizations measure and analyze the economic and broader development costs of conflict. While this conventional method of assessing the impact of conflict is fairly in-depth, it does not provide a comprehensive overview of a country or region embroiled in conflict. One of the earliest studies assessing the true cost of conflict on a variety of parameters was commissioned by Saferworld and compiled by Michael Cranna. Strategic Foresight Group has taken this science to a new level by developing a multi-disciplinary methodology, that has been applied to most parts of the world. A key benefit of using this tool is to encourage people to look at conflict in new ways and to widen public discussion of the subject, and to bring new insights to the debate on global security.
The main strategy and tactics of guerrilla warfare tend to involve the use of a small attacking, mobile force against a large, unwieldy force. The guerrilla force is largely or entirely organized in small units that are dependent on the support of the local population. Tactically, the guerrilla army makes the repetitive attacks far from the opponent's center of gravity with a view to keeping its own casualties to a minimum and imposing a constant debilitating strain on the enemy. This may provoke the enemy into a brutal, excessively destructive response which will both anger their own supporters and increase support for the guerrillas, ultimately compelling the enemy to withdraw. One of the most famous examples of this was during the Irish War of Independence. Michael Collins, a leader of the Irish Republican Army, often used this tactic to take out squads of British soldiers, mainly in Munster, especially Cork.
Hybrid warfare is a theory of military strategy, first proposed by Frank Hoffman, which employs political warfare and blends conventional warfare, irregular warfare, and cyberwarfare with other influencing methods, such as fake news, diplomacy, lawfare, regime change, and foreign electoral intervention. By combining kinetic operations with subversive efforts, the aggressor intends to avoid attribution or retribution. The concept of hybrid warfare has been criticized by a number of academics and practitioners due to its alleged vagueness, its disputed constitutive elements, and its alleged historical distortions.
In military history, the term "generations of warfare" refers to the concept of five "generations" in warfare, with each generation having different tactics, strategies, and technologies. The generations of warfare are sometimes dubbed as "4GW" or "5GW". The term originated in 1989 to describe "the changing face of war" over time, initially only referring to the emergence of the fourth generation, but eventually seeing the addition of a fifth generation.
