Developments in the Cuban revolution between mid-1959 and early 1960 demonstrate both the interaction between the international and domestic systems and the bargaining process involved in Cuban efforts to secure Soviet support. Until the dispatch of First Deputy Premier Anastas Mikoyan to Havana in early February 1960, the Soviet Union had been hesitant about revolutionary Cuba. The radicalization of the revolution which preceded Mikoyan's visit, therefore, stemmed not only from Fidel Castro's perception of opposition to his regime and from his need to ensure revolutionary momentum, but also from his efforts to increase Cuba's bargaining leverage with Moscow. In turn, the Cuban Communists served as a key linkage with Moscow and, most important, as an aggressive negotiating agent for Castro. In formulating their response to revolutionary Cuba, the Soviets were thus forced to contend with covert and overt pressures from Castro and his Communist allies.