In an article somewhat unfortunately entitled The Enduring Allure of Hitlerism, Ex-Army writes:
When "nationalism" comes up on this blog, some bozo always equates it to Naziism. These bozos are almost always leftists, and are consequently anti-nationalist and anti-Western. Now, the bozos aren't entirely wrong, because they know that nationalism isn't good for their ilk, any more than National Socialism would be. No, globalism is best for the bozos, and they instinctively know it. And while nationalism is not equivalent to National Socialism, the latter of course entails nationalism.
I suppose it is easy for people to look back on the course of German history and interpret almost anything that happened as contributing to the rise of Nazism. However, this leads to all kinds of distortions such as selectively quoting Johann Gottfried von Herder about his ideas on organic nationalism or excerpting the worst of Martin Luther's anti-Semitic screeds. Out of social and historical context, they could support the notion of ingrained German traits of contempt for other nationalities and blind obedience to authority. Herder did believe Christianity should be Germanized but he also preached tolerance for those of other nationalities and believed that other countries should adapt Christianity to their particular needs. Famously, Martin Luther insisted on the right of the individual to rebel against spiritual and intellectual authority. Neither of these contribute to a narrow-minded contempt of others nor to blind obedience to the state.
Ideas do have a power but that power is always subject to social and political circumstances. That reality is often forgotten -- or maybe just ignored -- by those who generalize from fantasies about the German character or mind to essential characteristics of fascism or Nazism.
Those who deride "nationalism" as some kind of fascist/Nazi sine qua non are delusional. The essence of fascism is not nationalism but statism. A national identity and support within the nation for that identity is not dangerous by itself. It is the concentration of power within the state that turns nationalism toxic.