Cuba established a socialist government led by Fidel Castro in 1959 and joined the Soviet Union, then the leading socialist country. However, Cuba did not join the Economic Mutual Aid Council (COMECON) until 1972, more than a decade after the socialist revolution.

One of the reasons for this delay is that, after the revolution, Cuba's initial focus was on strengthening its own political and economic system, rather than prioritizing participation in Comecon. 

Moreover, the Soviet Union did not actively promote Cuba's accession to ComeCon in the early days of the revolution, as it did not want to provoke the United States and risk escalating Cold War tensions.

In the late 1960s, Cuba faced serious economic difficulties due to trade restrictions imposed by the United States, prompting Cuba to seek closer economic ties with the Soviet Union and other socialist countries. This led the Soviet Union to view Cuba as an important regional ally and encouraged Cuba to join ComeCon.

In summary, Cuba's delay in joining COMECON was attributed to its initial focus on strengthening its political and economic system, the Soviet cautious approach to Cuba's entry during the early years of the Revolution, and Cuba's late 1960s was due to the growing economic difficulties of Deadline. This prompted it to seek closer ties with the Soviet Union and other socialist countries.