I would argue that it was Niebuhr's emphasis of idolatry as the primal sin from which all other sins are derived that gave him such theological and political clarity of vision. Indeed, nowhere is Niebuhr more impressive, both theologically and politically, when he speaks of modern idolatry in his Gifford Lectures, delivered in Scotland on the eve of World War II in 1939.
"In the life of every political group," he says, "whether nation or empire ... obedience is prompted by the fear of power on the one hand and by reverence for majesty on the other. The temptation to idolatry is implicit in the state's majesty." He then speaks of "the claim of moral autonomy by which the self-deification of the social group is made explicit by its presentation of itself as the source and end of existence." And most succinctly he states, "The nation pretends to be God."
What strikes me is the way that Niebuhr's critique of idolatry converges with that in the Jewish tradition, and how this then reframes the moral and political consequences of atheism in our time.It is a deep and profound reflection, well worth a read.