While the rising neocons were pushing for military action, US officials feared that a Soviet response could lead in a similar 1962 missile crisis with unknown consequences
“Secretary of State Henry Kissinger ordered a series of secret contingency plans that included airstrikes and mining of Cuban harbors in the aftermath of Fidel Castro's decision to send Cuban forces into Angola in late 1975, ...”
“Kissinger instructed General George Brown of the Joint Chiefs of Staff during a high-level meeting of national security officials on March 24, 1976, that included then Secretary of Defense Donald Rumsfeld. 'I think we are going to have to smash Castro,' Kissinger told President Ford. 'We probably can't do it before the [1976 presidential] elections.' 'I agree,' the president responded.”
“... Kissinger's consideration of open hostilities with Cuba came after a protracted effort of secret diplomatic talks to normalize relations [...] Cuba's efforts at supporting the anti-colonial struggle in Africa, the authors write, 'was the type of threat to U.S. interests that Kissinger had hoped the prospect of better relations would mitigate.'”
Kissinger is described as “apoplectic" with Castro for "Cuba's decision to deploy thousands of soldiers to Angola to assist the Popular Movement for the Liberation of Angola (MPLA) party of António Agostinho Neto against attacks from insurgent groups that were supported covertly by the United States and apartheid regime of South Africa. Concerned that Castro would eventually broaden his military incursion beyond Angola, Kissinger counseled Ford that they would have to 'crack the Cubans.'"
“In the March 24 meeting with an elite national security team known as the Washington Special Actions Group, Kissinger expanded on the domino scenario. 'If the Cubans destroy Rhodesia then Namibia is next and then there is South Africa,' Kissinger argued. To permit the 'Cubans as the shock troops of the revolution' in Africa, he argued, was unacceptable and could cause racial tensions in the 'Caribbean with the Cubans appealing to disaffected minorities and could then spillover into South America and even into our own country.' Moreover, the lack of a U.S. response to the global exercise of military power by a small Caribbean island nation, Kissinger feared, would be seen as American weakness.”
“Drafted secretly by the Washington Special Actions Group in April 1976, the contingency plans outlined punitive options that ranged from economic and political sanctions to acts of war such as mining Cuba's harbors, a naval quarantine, and strategic airstrikes 'to destroy selected Cuban military and military-related targets.'”
“The contingency planners warned Kissinger, however, that any act of aggression could trigger a superpower confrontation. Unlike the 1962 missile crisis, stated one planning paper, 'a new Cuban crisis would not necessarily lead to a Soviet retreat.' Indeed, 'a Cuban/Soviet response could escalate in areas that would maximize US casualties and thus provoke stronger response,' Kissinger's national security advisers warned. 'The circumstances that could lead the United States to select a military option against Cuba should be serious enough to warrant further action in preparation for general war.'”