Why did Soviet ships and goods become common in Havana after 1959?

Following the 1959 revolution, Cuba’s close ties with the United States were severed, leading Fidel Castro to turn to the Soviet Union for essential economic and military assistance. As the United States implemented a comprehensive trade embargo in the early 1960s, Cuba’s foreign trade shifted almost entirely toward the Soviet bloc.123

This geopolitical realignment made Soviet vessels a common sight in the port of Havana, while Soviet-made vehicles and various goods from the Soviet bloc became prevalent in the city’s streets and stores. This relationship was characterized by significant Soviet aid, including loans, petroleum, and war matériel, which were crucial to the Cuban government. Furthermore, the Soviet Union subsidized the Cuban economy by purchasing the majority of the country's sugar crop at prices often above those of the free market. By the end of the 1980s, nearly three-fourths of Cuba's trade was conducted with the Soviet Union on terms that were highly beneficial to the island.142