There were multiple political murders too. There were fistfights in parlament and screaming. But violence definitely was not just Soviet export. Communists were minority compared to right wing extremists - who started to operate right after WWI.

> But Hitler and his ideology were a product of First World War and not a product of unstable Germany or unstable Europe.

What does this mean? WWI itself was consequence of unstable Europe. Germany was heavily militarized culture even prior WWI. Their imperial ambitions were definitely pre existing.

Hitler tapped into nationalistic, racial and Darwinian trends that already existed.