<P> By the start of the century, the United States continued its interventionist attitude, which aimed to directly defend its interests in the region . This was officially articulated in Theodore Roosevelt's Big Stick Doctrine, which modified the old Monroe Doctrine, which had simply aimed to deter European intervention in the hemisphere . At the conclusion of the Spanish--American War the new government of Cuba and the United States signed the Platt Amendment in 1902, which authorized the United States to intervene in Cuban affairs when the United States deemed necessary . In Colombia, United States sought the concession of a territory in Panama to build a much anticipated canal across the isthmus . The Colombian government opposed this, but a Panamanian insurrection provided the United States with an opportunity . The United States backed Panamanian independence and the new nation granted the concession . These were not the only interventions carried out in the region by the United States . In the first decades of the twentieth century, there were several military incursions into Central America and the Caribbean, mostly in defense of commercial interests, which became known as the "Banana Wars ." </P> <P> The greatest political upheaval in the second decade of the century took place in Mexico . In 1908, President Porfirio Díaz, who had been in office since 1884, promised that he would step down in 1910 . Francisco I. Madero, a moderate liberal whose aim was to modernize the country while preventing a socialist revolution, launched an election campaign in 1910 . Díaz, however, changed his mind and ran for office once more . Madero was arrested on election day and Díaz declared the winner . These events provoked uprisings, which became the start of the Mexican Revolution . Revolutionary movements were organized and some key leaders appeared: Pancho Villa in the north, Emiliano Zapata in the south, and Madero in Mexico City . Madero's forces defeated the federal army in early 1911, assumed temporary control of the government and won a second election later on November 6, 1911 . Madero undertook moderate reforms to implement greater democracy in the political system but failed to satisfy many of the regional leaders in what had become a revolutionary situation . Madero's failure to address agrarian claims led Zapata to break with Madero and resume the revolution . On February 18, 1913 Victoriano Huerta, a conservative general organized a coup d'état with the support of the United States; Madero was killed four days later . Other revolutionary leaders such as Villa, Zapata, and Venustiano Carranza continued to militarily oppose the federal government, now under Huerta's control . Allies Zapata and Villa took Mexico City in March 1914, but found themselves outside of their elements in the capital and withdrew to their respective bastions . This allowed Carranza to assume control of the central government . He then organized the repression of the rebel armies of Villa and Zapata, led in particular by General Álvaro Obregón . The Mexican Constitution of 1917, still the current constitution, was proclaimed but initially little enforced . The efforts against the other revolutionary leaders continued . Zapata was assassinated on April 10, 1919 . Carranza himself was assassinated on May 15, 1920, leaving Obregón in power, who was officially elected president later that year . Finally in 1923 Villa was also assassinated . With the removal of the main rivals Obregón is able to consolidate power and relative peace returned to Mexico . Under the Constitution a liberal government is implemented but some of the aspirations of the working and rural classes remained unfulfilled . (See also, Agrarian land reform in Mexico .) </P> <P> Sports became increasingly popular, drawing enthusiastic fans to large stadia . The International Olympic Committee (IOC) worked to encourage Olympic ideals and participation . Following the 1922 Latin American Games in Rio de Janeiro, the IOC helped to establish national Olympic committees and prepare for future competition . In Brazil, however, sporting and political rivalries slowed progress as opposing factions fought to control of international sport . The 1924 Summer Olympics in Paris and the 1928 Summer Olympics games in Amsterdam saw greatly increased participation from Latin American athletes . English and Scottish engineers brought futebol (soccer) to Brazil in the late 1800s . The International Committee of the YMCA of North America and the Playground Association of America played major roles in training coaches...</P> <P> The Great Depression posed a great challenge to the region . The collapse of the world economy meant that the demand for raw materials drastically declined, undermining many of the economies of Latin America . Intellectuals and government leaders in Latin America turned their backs on the older economic policies and turned toward import substitution industrialization . The goal was to create self - sufficient economies, which would have their own industrial sectors and large middle classes and which would be immune to the ups and downs of the global economy . Despite the potential threats to United States commercial interests, the Roosevelt administration (1933--1945) understood that the United States could not wholly oppose import substitution . Roosevelt implemented a Good Neighbor policy and allowed the nationalization of some American companies in Latin America . Mexican President Lázaro Cárdenas nationalized American oil companies, out of which he created Pemex . Cárdenas also oversaw the redistribution of a quantity of land, fulfilling the hopes of many since the start of the Mexican Revolution . The Platt Amendment was also repealed, freeing Cuba from legal and official interference of the United States in its politics . The Second World War also brought the United States and most Latin American nations together . </P>

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