Butler participated in a series of occupations, "police actions" and interventions by the United States in Central America and the Caribbean, later called the Banana Wars because their goal was to protect American commercial interests in the region, particularly those of the United Fruit Company. This company had significant financial stakes in the production of bananas, tobacco, sugar cane, and other products throughout the Caribbean, Central America, and the northern portions of South America. The U.S. was also trying to advance its own political interests by maintaining its influence in the region and especially its control of the Panama Canal. These interventions started with the Spanish–American War in 1898 and ended with the withdrawal of troops from Haiti and President Franklin D. Roosevelt's Good Neighbor policy in 1934. After his retirement, Butler became an outspoken critic of the business interests in the Caribbean, criticizing the ways in which American businesses and Wall Street bankers imposed their agenda on U.S. foreign policy during this period.