Well, he supposedly doen't have immunity in Chile, since part of the rationale for returning him is that he can be prosecuted in Chile for crimes committed there. Who are you saying offered it to him?

And Castro is not about to invest any trust in the U.S. government to leave him in peace, whatever happens to Pinochet. After all, the U.S. has been in a state of hostility or outright war with him for the past forty years! The equation between Castro and Pinochet does not hold up at all, since Pinochet took power with U.S. complicity, and provided opportunities for U.S. based corporate investment in his dictatorship.

There's a big distinction between how your Communist and capitalist dictators are permitted to step down...look up Baby Doc Duvalier or Imelda Marcos.

Willie-O