The western democracies have never taken fascism seriously. The story that Britain and America tell themselves is that they led a great crusade against it in World War II. This is bollocks. They were dragged into WWII through the way military alliances fell and not out of any kind of principled opposition to what Germany, Japan and Italy were doing politically. That's just a story they tell themselves to soothe national egos.
Indeed, afterwards they did almost nothing to prevent it taking root in their own societies, beyond trying to construct welfare states. As carrot and stick approaches go, this was the carrot. There was no stick, and fascism needs a stick to keep it down.
The welfare state model held it at bay for a few decades, until the kids of the people who built it grew up and realised they could vote in the people who would dismantle it for cash and hand enough of it over to them to drive a Faustian bargain that fucked their own children.
There was never any systemic attempt to build political resilience against fascism in those societies because, frankly, fascist sympathies are too heavily embedded within the ruling classes and security services of those countries, and removing them would involve a level of pain and commitment to principle that those in a position to actually do so are not willing to entertain.
What should be, at a bare minimum, in place is a commitment to uncovering and removing fascism from all levels of public life, backed by robust and mandatory civics education.
Western democracies are utterly incapable of doing this, and instead think that they can accommodate their own fascist undercurrents without them becoming overwhelming.
But with the dismantling of their own welfare states, they have nothing to fall back on, and so when economic shocks hit, the shit they have been hiding rapidly bubbles to the surface.
We live in societies of rulers causally throwing lit matches at pools of petrol surrounding their ankles, and relying on the fact that there's enough breeze to blow them out before they land.
One day there won't be.