It's more embedded into the culture, going farther back. When Japan underwent the Meiji "Restoration" they were trying to maintain stability, sword use was restricted to officers, guns were not easy to obtain just yet.
I'm not surprised that this concept would be renewed and expanded under Allied occupation post-WWII. The whole point was defanging a beaten dog.
It's more embedded into the culture, going farther back. When Japan underwent the Meiji "Restoration" they were trying to maintain stability, sword use was restricted to officers, guns were not easy to obtain just yet.
I'm not surprised that this concept would be renewed and expanded under Allied occupation post-WWII. The whole point was defanging a beaten dog.