American imperialism is the exercise of power or control by the US outside its borders. The US expanded its territory initially via conquest, later shifting to controlling/influencing other countries without conquest, using techniques such as alliances; aid; gunboat diplomacy; treaties; trade; support for preferred political factions; regime change; economic influence via private companies, exports of culture and media. Military interventions have been used to support allies, expel invaders, overthrow governments, and support US economic interests.
American imperialism and expansionism took the form of "New Imperialism" beginning in the late 19th century, although authors such as Daniel Immerwahr consider earlier American territorial expansion across North America at the expense of Native Americans to fit the definition. While the US has never officially identified itself and its territorial possessions as an empire, some commentators have done so, including Max Boot, Arthur M. Schlesinger Jr., and Niall Ferguson. Other commentators have accused the US of practicing neocolonialism—dominating territory via indirect means—which leverages economic power rather than military force.
