Question

What conditions led to the development of feudalism in both Western Europe and Japan

Answer 1

After the Allies defeated the Axis powers in World War Two. The Allies set up puppet governments of capitalism to help rebuild the countries faster.

Answer 2

I believe the answer is: in both cases government loses power to local chiefs

After the lost of power, the chiefs managed to established their own territories and divide both Europe and Japan into several parts. Later on, these chiefs started to hire their own military (knights and samurais) , and they also develop their own economic policies.