The New York Review of Books republished an essay by Isaiah Berlin on Machiavelli:
Machiavelli’s cardinal achievement is his uncovering of an insoluble dilemma, the planting of a permanent question mark in the path of posterity. It stems from his de facto recognition that ends equally ultimate, equally sacred, may contradict each other, that entire systems of value may come into collision without possibility of rational arbitration, and that not merely in exceptional circumstances, as a result of abnormality or accident or error—the clash of Antigone and Creon or in the story of Tristan—but (this was surely new) as part of the normal human situation.
(Read the article here.)
There is a common and widespread bias in favor of sacred ends; people tend to forget that there are indeed equally sacred ends that contradict the first sacred ends.
Morality is a dilemma but it is usually presented as a command with a few exclamation marks.