The Union of South American Nations (USAN), sometimes also referred to as the South American Union, abbreviated in Spanish as UNASUR and in Portuguese as UNASUL, is an intergovernmental regional organization set up by Hugo Chavez to counteract the influence of the United States in the region. It once comprised twelve South American countries; as of 2019, most have withdrawn.

Hugo Rafael Chávez Frías was a Venezuelan politician and military officer who served as president of Venezuela from 1999 until his death in 2013, except for a brief period of forty-seven hours in 2002. Chávez was also leader of the Fifth Republic Movement political party from its foundation in 1997 until 2007, when it merged with several other parties to form the United Socialist Party of Venezuela (PSUV), which he led until 2012.