I happen to think that on the whole the U.S. has been a more altruistic state implementing its power than some of those in the past, but I am not naive enough to think it was all altruism or devoid of self-interest.
"No religion is true, but some religion, any religion, is politically necessary. Law and morality are insufficient for the large majority of men. Obedience to the law and to the morals are insufficient for making men happy. […]Law and morality are therefore in need of being supplemented by divine rewards and punishments."