For Cuba, the original SCD was the Soviet Union. The 90s were rough, as Cuba's flow of support for Moscow dried up after the USSR went the way of the dodo.
In the later 00s to today, SCD 2.0 showed up in the form of Hugo Chavez, who gives Havana cut-rate oil and treats Cuban doctors and teachers as export goods simpatico with Chavez's socialist strong-man MO.
That Chavez is knocking on Heaven's door (they might say yes, he's got a bit of Catholic in him that might flower in that fortnight-to-hanging clarity) in Havana's best hospital is an indication that Chavez sees himself as Fidel's kid brother from another mutha with the oil money.
Not everyone in the Chavez camp are Castro Convertibles, to borrow from the Spy-v-Spy running gag. The gravy train could well shut down if the wrong (for the Castros) guy takes over for Chavez if and when he passes on. VP Nicolas Maduro is a fellow fatigues-sniffer, but the rest of the Bolivarian camp isn't as pro-Cuba, let alone the opposition that might win a by-election that would be required if Chavez passes quickly.
Interesting times, indeed. Some good, albeit a bit morbid, news to take your mind off some of the execrable news from DC.