Disclaimer: Once again, I AINT defending Castro.
"There are other ports he can trade with, and get good prices from. He just ain't to any significant degree."
StSanta, if you own a bussiness and you trade with the US, you WONT trade with Cuba. Period. The very moment US finds out you do, they will cut you off. My family owns a chemical distribution company back home, Cuba was a great market to push into... problem was, if we did we lost more than half of our costumers in the US, our tax benefits (for trading with US), and most of our source of raw materials.
So it aint that Cuba doesnt go into other markets, its that the other markets cant afford to trade with Cuba, because if they do Big Brother USA will cut off US trade and benefits to them.
So go figure.