Believing support for the revolution was waning, Cuba’s president Fulgencio Batista called for a major military offensive against Fidel Castro‘s rebels in the Sierra Maestra mountains in the summer of 1958.
But the rebels turned back the offensive, forcing the army to withdraw.
With international media giving favorable press coverage to the revolutionaries, the United States began to withdraw support for Batista’s government, which it had previously backed due to the dictator’s anti-communist stance.
Source: History.com