Which they've been doing to Castro since 1959, and in all that time he's never come up with anything to equal Camp X-ray or Abu Grahib.
What would Cuba look like today if the US had allowed them to trade and not interfered politically?
They would be wealthier. Cuba has been denied access to the largest market in the world.
The Cuban Missile Crisis never would have occurred because we know from Soviet documents that Castro didn't want them there. He acceded to missiles only because he had to.
There would have been an opportunity for the international community to push for democratic reforms. That has been largely impossible because of the USA's constant support for restoring power to a few elites.