By “of a piece,” I mean we identified the governing parties of Germany, Italy, Spain, Hungary, Romania, and the various fascistic movements arising in other nations as being ideologically aligned and interrelated, even if each (by definition) had purely national aspects not shared by some of the others. We didn’t identify Nazism as a thing that happened in isolation from what had happened in Italy, even if the mysticism,antisemitism and extreme racism of Nazism were not central, defining features of Italian fascism. And that understanding led people, and people in the Roosevelt Administration in particular, to hear what people like Charles Coughlin or even Huey Long were saying, and what was going on various South American countries in a very different way than they otherwise might have.
You can definitely overdo it. You can end up seeing ghosts and hunting witches. But there is something systemic going on here. We have a lot of things going on at once in a lot of countries at the same time–the continuing aftereffects of the 2008 crash, the exact kind of mass migration of economic and war refugees from south to north that smart people in the 90s warned climate change would cause, and a growing sense that democratic governments have been captured by elites–that are undermining faith in democracy itself and leading people to accept the stealthy imposition of Putinist regimes.
A lot of it is enabled by pure cynicism and despair. It is enabled above all by people who can’d deal with shades of grey, people who wrongly think that their democracy is already an authoritarian regime with a secret police force and a layer of kleptocratic regime vassels because they can’t see that huge differences in degree are differences in kind until it’s too late.