Do Cubans under Castro agree to their social contract?
If you define contracts as voluntary, then you probably wouldn’t say the Cuban government operates by social contract, since most people who wanted to emigrate have not been permitted to. Most libertarians have a peculiar definition of voluntary: contractual agreement makes all requirements of the contract “voluntary”, no matter how unexpected they are, no matter how long the contract lasts for, no matter if the contractee changes his mind. However, they’re seldom willing to view our social contract in that manner. Our social contract in the USA is one of the nice, voluntary contracts that libertarians should like. Even better, because you can terminate it by leaving at any time. There is no US government obstacle to emigration from the US.