I agree that the U.S. made sure that neither Allende, Arbenz, nor the Sandanistas had *any* chance of building a good society. I suspect that their chances were very slim in any event (which may be a defensive rationalization), but slim is different from zero. I agree that U.S. policy toward Afghanistan since 1979 has been *criminal* and *counterprodutive*: there are things much worse than post-Stalin and post-Mao really existing socialism, and U.S. policy has created them in Afghanistan today.
My "favorite," however, remains the U.S. "tilt" toward Pakistan and away from India during 1970-1: strong U.S. support for Yahya Khan's attempt to kill everyone who could read in what is now Bangladesh. Approve of the killing of a million people just because the Pakistani government had let itself be used as a base so Henry Kissinger could meet with Zhou Enlai without alerting William Rogers...
I agree that the U.S. embargo of Cuba is *stupid,* *counterproductive,* and cruel.
But I don't think Cuba would be much different today if U.S. governments over the past generation had treated it as they treated Poland. And I don't think that the U.S. had much to do with the destiny of the Soviet Union, China, or their Eurasian satellites...
Brad Delong