I have a pet theory that facism is very much an inability to look in the mirror but when someone else does it it's a different story. The first country out of the countries assumed to be... Let's say predominantly assumed Christian in heritage and treat each other as peers - the ones who serve as the closest analog of mutually assumed standards - becomes the first adopter of Facism. That might be the actual shock that shuts down facism elsewhere. Wherever does it first seems to me likeliest to become the example that causes people on the fence to snap out of it.

Pre WWII there were facist groups on the rise everywhere. While it's possible it may have been more in reaction to Germany's sudden expansionism the drop off of those who were heading into moderate support towards facist groups could have been essentially just realizing what your ideology looks like fully complete from the outside for the first time and being repulsed.

I have zero anything to back this up. Maybe it's more just a hope than anything.