The Mexican-American War, occurring during a time of domestic revolts and uprisings worldwide, did not attract significant international attention. The established Monroe Doctrine deterred foreign interference in the Western Hemisphere, potentially limiting global reactions.
While the United States received some support, particularly from Britain, France, and other countries with economic interests in the region, there was also criticism and concern about American expansionism and the legitimacy of the war. Some countries, such as Mexico's ally, Spain, expressed opposition to the conflict. Overall, the war generated mixed international reactions, reflecting different perspectives and interests among nations.