If I were to distill Judt's points into a few key ideas, it is that "history matters"; that oppressors and tyrants are invariably interested in concealing their culpability, while "innocent citizens" are likewise inclined to minimize their own involvement in the crimes of their governments; and that bad myths give rise eventually to bad politics -- more conflict, more tyranny, more violence. So the work of honest history is crucial to humanity's ability to achieve a better future.
Is there a lesson for us in the United States? There is indeed. We must confront the difficult realities of racism, nationalism, bigotry, and authoritarianism that have simmered throughout the decades and centuries in the United States, and that have broken into a boil under the Trump presidency. Tony Judt is right here: the myths of one decade become the action principles of the next.