Russell Kirk, in a lecture delivered for the Heritage foundation in the early 1980's addressed the question whether America had "a mission, providentially ordained."
Kirk believed it did and, without expressing his own concept of the mission, aligned himself with the ideas of Orestes Brownson (1805-1876) whom he describes as "a considerable political philosopher, a seminal essayist on religion, a literary critic of discernment, a serious journalist with fighting vigor, and one of the shrewder observers of American charaacter and institutions."
Brownson described the mission as "not so much the realization of liberty as the realization of the true idea of the state, which secures at once the authority of the public and the freedom of the individual - the sovreignty of the people without social despotism, and individual freedom without anarchy. In other words, its mission is to bring out in its life the dialectrical union of authority and liberty, of the natural rights of man and those of society. The Greek and Roman republics asserted the state to the detriment of individual freedom; modern republics either do the same, or assert individual freedom to the detriment of the state. The American republic has been instituted by Providence to realize the freedom of each with advantage to the other."
Kirk refines this by writing "The American Republic has the mission of reconciling liberty and law."
This is a centrist position, somewhat like favoring a mixed economy. It seems reasonable.
In today's fervid political environment, some on the Right challenge the opposition with the charge of not believing in American Exceptionalisim. This term is very subjective in nature but at the present time it seems to mean that "America is the greatest country in the world now and forever." That is not a mission, divinely ordained. That is a state of being or consciousness that lives with the support of Pride, one of the Seven Sins.
Orestes Brownson used the terms humanitarian and social democrat to identify the threat to the American Mission. "The humanitarian democracy," Brownson wrote, "which scorns all geographical lines, effaces all individualities, and professes to plant itself on humanity alone, has acquired by the (Civil) war new strength, and is not without menace to our future." He forsees attacks on differences between the sexes, and on private property (as unequally distributed). "Nor can our humanitarian stop there. Individuals are, and as long as there are individuals will be, unequal; some are handsomer and some are uglier;some wiser or sillier, more or less gifted, stronger or weaker, taller or shorter, stouter or thinner than others, and therefore some have natural advantages which others have not. There is inequality, therefore injustice, which can be remedied only by the abolition of all individualities, and the reduction of all individuals to the race, or humanity, man in general. He (the humanitarian) can find no limit to his agitation this side of vague generality, which is no reality, but a pure nullity, for he respects no territorial or individual circumscriptions, and must regard creation itself as a blunder."
Brownson's remarks have to be one of the earliest (1848) critical responses to the publication of Das Kapital and the advent of Marxism. Of course, Brownson could not forsee that our humanitarian urges would sweep us into foreign adventures, said efforts variously described as 'improving the lives of others', 'meeting our obligations abroad', 'making the world a better place', etc. The Nanny State is wrong but being a Nanny Nation to the world is not? This is one of the major contradictions in the domain of modern conservative politics.