In December 1989 the United States invaded Panama to depose the dictator Manuel Noriega. Since the U.S. invasion, and resulting end to the 21-year military dictatorship, Panama has successfully completed four peaceful transfers of power to opposing political factions. The political landscape is dominated by two major parties and many smaller parties, many of which are driven by individual leaders more than ideologies. Former President Martin Torrijos is the son of dictator Omar Torrijos. He succeeded Mireya Moscoso, the widow of Arnulfo Arias. Panama's most recent national elections occurred on May 4, 2014 with Incumbent Vice-President Juan Carlos Varela declared the victor.