Who started the Mexican-American War and how did it affect relations with the United States?
Historians are in agreement that the US government, led by President James K. Polk, provoked Mexico into fighting a war to protect its national territory from US intervention. Polk had blatant territorial ambitions, and in 1845 the US Congress approved the annexation of the independent Republic of Texas, which Mexico still considered to be part of its national territory. Polk was not satisfied with Texas alone and wanted to buy part of New Mexico and California. The Mexicans refused his offer, and Mexican and US forces clashed briefly. Congress then declared war on Mexico on May 13, 1846. The United States invaded Mexican territory in New Mexico, California, and Texas, and occupied the port of Veracruz. General Winfield Scott led troops from Veracruz to Mexico City, taking the capital after a bitter fight in March 1847. Mexico's resistance to the US invasion is best symbolized by the deaths of six military cadets, known as Los Ninos Heroes (The Child Heroes), who jumped off Chapultepec Castle rather than surrender. The United States used its occupation to force the 1848 Treaty of Guadalupe Hidalgo on Mexico, in which Mexico lost 55 percent of its national territory, including all or parts of Nevada, Colorado, Utah, California, Arizona, New Mexico, and Texas, in exchange for $15 million.
The United States' aggression toward Mexico increased Mexicans' sense of nationalism, particularly as directed toward the United States, elements of which exist to date. These historic events led to Mexico's distrust of the United States. This distrust not only has been reflected in the public posture of Mexico toward the United States in its bilateral relationship with its northern neighbor, but also can be found in concrete policy decisions. Until the 1990s, the stated national security mission of the Mexican armed forces was to defend Mexico at all costs from a US invasion. The Mexican Army's unwillingness to collaborate significantly with the US military is a consequence, in part, of this historic event. After the revolution, Mexico passed laws (directed largely at Americans) preventing foreigners from owning any property within a certain distance of its borders, as well as indirectly, through a Mexican representative, owning real estate anywhere else in Mexico. These restrictions on property ownership can be traced back to the Mexican-American War and the way in which Polk and the Democratic Party used the Texas Republic (to which Mexico had allowed heavy immigration by US settlers) to establish a foothold for the United States in its northern territories. Finally, a convincing argument can be made that Mexico lagged behind most other Latin American countries in pursuing a democratic political model in the 1980s and 1990s in part because the governing party, the Institutional Revolutionary Party (PRI), maintained a strongly nationalistic posture toward its democratic neighbor.