We have a responsibility??? please...that kind of idiotic thinking got us into Iraq. We do not even have the right to interfere in other countries' affairs, let alone the responsibility.
Why's that?
So if I understand you correctly: it makes no diference if a government was democratically elected, and retains popular support from its people, but if it isn't a U.S. ally, or even worse, if it actively criticizes the U.S., then we have an obligation to remove its leaders from power, even if it poses no acute threat to us. See some problems with that reasoning?