Foreign interventions by the United States
The United States has been involved in numerous foreign interventions throughout its history. By the broadest definition of military intervention, the U.S. has engaged in nearly 400 military interventions between 1776 and 2023, with half of these operations occurring since 1950 and over 25% occurring in the post-Cold War period. Common objectives of U.S. foreign interventions have revolved around economic opportunity, social protection, protection of U.S. citizens and diplomats, territorial expansion, fomenting regime change, nation-building, and enforcing international law.
There have been two dominant schools of thought in the United States about foreign policy—interventionism, which encourages military, diplomatic, and economic intervention in foreign countries—and isolationism, which discourages these.
The 19th century formed the roots of United States foreign interventionism, which at the time was largely driven by economic opportunities in the Pacific and Spanish-held Latin America along with the Monroe Doctrine, which saw the U.S. seek a policy to resist European colonialism in the Western hemisphere. The 20th century saw the U.S. intervene in two world wars in which American forces fought alongside their allies in international campaigns against Imperial Japan, Imperial and Nazi Germany, and their respective allies. The aftermath of World War II resulted in a foreign policy of containment aimed at preventing the spread of world communism. The ensuing Cold War resulted in the Truman, Eisenhower, Kennedy, Carter, and Reagan Doctrines, all of which saw the U.S. embrace espionage, regime change, proxy conflicts, and other clandestine activity internationally against the Soviet Union.
After the Soviet Union collapsed in 1991, the U.S. emerged as the world's sole superpower and, with this, continued interventions in Africa, Eastern Europe, and the Middle East. Following the September 11 attacks in 2001, the Bush Administration launched the "War on terrorism" in which the U.S. waged international counterterrorism campaigns against various extremist groups such as al-Qaeda and the Islamic State in various countries. Several U.S. allies, notably the United Kingdom, took part. The Bush Doctrine of preemptive war saw the U.S. invade Iraq in 2003 and saw the military expand its presence in Africa and Asia via a revamped policy of foreign internal defense and counter-terrorism. The Obama administration's 2012 "Pivot to East Asia" strategy sought to refocus U.S. geopolitical efforts from counter-insurgencies in the Middle East to increasing American involvement in East Asia, as part of a policy to contain an ascendant China, a trajectory also continued by the Trump and Biden administrations.
The United States Navy has been involved in anti-piracy activity in foreign territory throughout its history, from the Barbary Wars to combating modern piracy off the coast of Somalia and other regions.