There’s a very simple reason (but it’s not the only reason): A significant section of the Russian military was supportive of the Revolution. Whereas in Italy and Germany, the military was by and large in favor of the fascists, by the time they were ready to ascend to power. So, in Russia, the military facilitated the Revolution, whereas in Europe, the military crushed the Revolutions.

Especially in Germany, where the loss during WW1 was attributed largely to the Social Democrats (who were pushing for an armistice), and a poor leadership ranging from the monarch to the government, as well as the nobility and the higher echelons of the officer corps. Put simply, the military hated the “leftists” and didn’t really trust any other politicians except Hitler with his messages of strength, unity and revenge.

In Italy, the Vatican gradually grew in favor of Mussolini (which ended up resulting in the Vatican’s independence). Virtually every priest became a propaganda officer for fascism. As a result, the military was in support of Mussolini early on.

And a second reason to consider (again, there’s more reasons): The October Revolution shook things up in the rest of Europe. German communists were also getting ready to seize power, and it was clear things were about to happen in France, Spain, Italy, Poland, Romania, Bulgaria, Hungary and Greece. The capitalists and reactionaries in those countries coalesced to stop the communists before they could begin their own revolts, and they saw fascists as the natural solution. Especially in Italy, where the industrialists started heavily funding Mussolini almost immediately after he formed his movement.

There’s many other reasons, like the popular mentality and culture, the nihilism of Western European communists after the failures of the Paris Commune and the more recent Spartacist Revolt, the more developed capitalist forces that permeated every facet of government and security, the large labor aristocracy that inhabited the major population centers in those countries, etc.

This is just my opinion and i’m sure there’s a more scientific answer but i’d say it has a lot to do with imperialism. Germany and Italy were historically among the main imperialist powers and as such had both a population with a mentality shaped by imperialism/colonialism as well as the material preconditions that made them more prone to fascist takeover rather than socialist revolution. Russia, though it sounds paradoxical, was an empire in name but not a highly developed imperialist power in the way the western Europeans were.

Russia was very underdeveloped and its capitalist system was not yet fully established (having just emerged out of semi-feudal conditions), such that its capitalist class was too weak to be able to take undisputed control when the monarchy fell. In addition its population was not as accustomed as that of Western Europe to living in (comparative) luxury on the basis of colonial wealth extraction. Their population was still mainly peasant class and did not yet have a developed imperial core mentality of entitlement and superiority over other peoples.

On the other end of the scale you have Britain and France where you also didn’t see the kinds of fascist coups you saw in Germany and Italy. And this is to do with the fact that, certainly after the First World War, these were merely second tier imperialist powers, while Britain and France were the main colonial powers and were able to extract so much colonial plunder that their capitalist class did not consider open fascism necessary. They could still afford to bribe their population and maintain absolute control as well as high profits under a liberal-bourgeois “democratic” model.

In short it was not necessary to institute open fascist dictatorship in Britain and France because the dominance of the capitalist class there was absolute, their populations too docile on account of the benefits of living in the core of the two largest colonial empires in the world and so posed little to no threat of socialist revolution. Bourgeois “democracy” is the preferred system for capital under conditions of abundant super-profits and a politically neutered working class. Open fascism is sort of a last resort as it creates too much instability and opposition.

And this model has worked for a long time now in Europe and the Anglo colonial nations as they managed after the Second World War, through a mixture of material benefits and cultural indoctrination, to turn their populations into highly docile and servile cultures that had almost no thought of rebellion or uprising. This is now slowly changing as the material conditions for that are going away but the culture of capitalist bootlicking is still very much entrenched. That coupled with the pervasive racism and convictions of cultural superiority means that we are now again entering ideal conditions for fascism.

That’s the magic of fascism, it has the uncanny power of coopting people’s indignation with current reality and seduce them with easy answers, like you are fucked because THEM(pick your oppressed group here) are fucking you, therefore if we go to war with THEM everything will be wonderful, and that’s quite a false promise but it sounds true and people want to believe that something will change.

That being said both Germany and Italy had quite expressive communist movements, especially Italy, they would likely have made more of a splash in their after war elections had CIA not meddled with it. So it’s important to understand that both communism and fascism somewhat run on the same fuel, and a well organized vanguard can defend from fascist proliferation, and the same goes the other way, a strong fascist movement can take the wind out of communist movement’s wings. That’s one of thr many many reasons the hatred is so strong and mutual between the two groups, and why capitalism helps fascist movements when they fuck shit up

The Imperial Russian state had also almost completely disintegrated in large parts of the country. The disastrous campaigns on the Eastern Front resulted in the mobilization of large numbers of able-bodied men from the rural state security forces, while also producing massive waves of deserters, many of whom dispersed into the countryside and became bandits preying on travellers and the peasantry. When the revolutionaries stepped up, and especially when the Bolsheviks took power, they returned state control and infrastructure to these areas, solidifying them as the only legitimate state power. Meanwhile in Germany, although losing WW1 shook up the state and got the Kaiser deposed, the state never lost control over its territory in the same way. And as OrnluWolfjarl says, when the Imperial Army recalled units from the front line to crush the communists, by the time they’d marched all the way back to the heartlands a majority of the soldiers had changed allegiance and just joined the Red Army instead.