Correct. All it takes is to read 'The Ugly American' to see that.It's cowboy politics. If we stop trading with them all we're doing is starving people, and those states then get to use anti-US sentiment and feelings of intereference with national sovereignity to increase the popularity of their regime.
Cuba wouldn't have lasted half this time without the blockade. In fact, if we had just not treated Castro like a piece of shit, he probably never would have reverted to the USSR and Cuba would've probably become a democracy by now.