Adolf Hitler and Nazism - after all these years - have remained morally instructive and perhaps even more so now.

One of Russian President Vladimir Putin's strangest justifications for the invasion of Ukraine - or the "special military operation" as he described it - is saving innocent civilians by "de-Nazifying" the country and toppling the government in Kyiv, which he claims has been seized by "extreme nationalists and neo-Nazis", even though Ukrainian President Volodymyr Zelensky is Jewish and had relatives who perished in the Holocaust.