Final answer:
The United States intervened in the Dominican Republic's politics in 1965 to prevent a Socialist leader from returning to power by sending U.S. troops and establishing a conservative government.
Step-by-step explanation:
The U.S. intervention in the Caribbean island nation's politics to prevent a Socialist leader from coming to power specifically refers to the Dominican Republic.
The historical context dates back to 1965 when the U.S., under President Lyndon Johnson, sent twenty-two thousand troops to prevent a communist takeover in the Dominican Republic.
This action was taken after a revolt by liberal officers aiming to restore Juan Bosch, a liberal reformer previously ousted by the Dominican army. The motive behind the U.S. involvement was to install a more conservative, non-communist government.