Via L&P, a good piece in the Grauniad about the actual motivations behind the second world war. Right or wrong, WWII was a practical war against a geopolitical rival, not a crusade for justice or human rights.
Combining it with the latest excellent essays from Mencius (1, 2, more still to come), it would seem that the conventional wisdom is reversed: the first world war was an ideological war, fought in the name of democracy, while the second was a pragmatic struggle for power and influence.
It would be consistent with my theory of Humanitarian Intervention (and why not to do it), that the war fought for realpolitik has proved easier to justify in hindsight than the war fought for democratic ideology.