Rafael Trujillo ruled the Dominican Republic from 1930 to 1961 through violence, fear, and oppression, using secret police and assassinations to stay in power. He was especially cruel to dissenters and Haitians, as seen in the 1937 Parsley Massacre. In The Brief Wondrous Life of Oscar Wao, Trujillo's regime deeply affects Oscar's family—his grandfather Abelard is imprisoned for protecting his daughter from Trujillo, and his mother Beli is severely beaten by his men. The novel portrays Trujillo’s cruelty as a generational curse (fukú) that continues to harm Dominican families long after his death.

In The Brief Wondrous Life of Oscar Wao, Dominican values like family loyalty, machismo, and gender roles shape the characters' lives. La Inca shows sacrifice, while Beli reflects generational trauma. Yunior fits the macho ideal, but Oscar’s rejection of it makes him an outsider. The novel also explores race, immigration, and identity, showing how Trujillo’s legacy deepened anti-Blackness and cultural conflict. Díaz uses these themes to challenge Dominican norms and reveal history’s lasting impacts on identity.