Venezuela's oil was part neocolonial Monroe Doctrine and part strangle Cuba so its government would "fall" by choking off its petrochem supply chain from Mexico and Venezuela. Cuba I don't think will fall, even if it's reduced to the Stone Age.
As in, the regime will cling to power, damn the cost (which the people, not the oligarchs, will incur)? Or do you mean to imply the Cuban people support the dictatorship?