That is the problem with the slow, inexorable growth of Government. Entitlements become an addiction worse than heroin. When it comes time to implement spending austerity, you can't do it without throwing your whole society into upheaval and chaos. Thirty years ago it would have been painful, but doable. Now it like surgery without anesthetic.
The US will have the same problem when the time comes, and probably worse. Greece is a fairly homogeneous country—we are not. Even Spain might break up because of its austerity.