In 1947 Dominican exiles, including Juan Bosch, had concentrated in Cuba. With the approval and support of Cuba's government, led by Ramón Grau, an expeditionary force was trained with the intention of invading the Dominican Republic and overthrowing Trujillo. However, international pressure, including from the United States, made the exiles abort the expedition. In turn, when Fulgencio Batista was in power, Trujillo initially supported anti-Batista supporters of Carlos Prío Socarrás in Oriente Province in 1955; however, weapons Trujillo sent were soon inherited by Fidel Castro's insurgents when Prío allied with Castro. After 1956, when Trujillo saw that Castro was gaining ground, he started to support Batista with money, planes, equipment, and men. Trujillo, convinced that Batista would prevail, was very surprised when Batista showed up as a fugitive after he had been ousted. Trujillo kept Batista until August 1959 as a "virtual prisoner." Only after paying US$3-4 million could Batista leave for Portugal, which had granted him a visa.
Trujillo's "central arch" was his instinct for power. This was coupled with an intense desire for money, which he recognized as a source of and support for power. Up at four in the morning, he exercised, studied the newspaper, read many reports, and completed papers before breakfast. At the office by nine, he continued his work, and took lunch by noon. After a walk, he continued to work until 7:30 pm. After dinner, he attended functions, held discussions, or was driven around incognito in the city "observing and remembering." Until Santo Domingo's National Palace was built in 1947, he worked out of the Casas Reales, the colonial-era Viceregal center of administration. Today the building is a museum; on display are his desk and chair, along with a massive collection of arms and armor that he bought. He was methodical, punctual, secretive, and guarded; he had no true friends, only associates and acquaintances. For his associates, his actions towards them were unpredictable.