Whenever there is a debate over the efficacy of sanctioning an authoritarian state, the supporters of the economic war have to resort to the equivalent of a body count to back up their claims.
The US, after the Cuba revolution, argued that a socialist or communist economic system would fail in Cuba. Obviously, the US did not believe this because it imposed sanctions, sanctions that stiffened over time, yet the Cuban people persist against this oppression. The people suffer horribly. These are the people the US says they wanted to benefit from the sanctions. Tens of thousands of Cubans were born and died under US sanctions. Sanctions that equal terrorism and crimes against humanity. Where would Cubans have been today if US sanctions had not been imposed? Why wouldn't the US give the revolution a chance?
Nixon and Kissinger answered this question when the CIA engineered a coup d'etat in 1973 against the democratically elected socialist government of Chile under President Salvador Allende. The CIA proxy was General Pinochet who oversaw a regime of terror and the killing and torturing thousands after taking power.
Nixon and Kissinger said that if Chile were successful economically it would be a "bad" example for other South American countries. "Bad" meaning they would elect the same form of government; good for the people, bad for US corporations. Et tu Cuba?