The point about commingling and separation was made by Ito Satoshi in a collection of essays cited in my bibiography. Edited by Nobutaka Inoue, it is entitled Shinto: A Short History
. If you want to hone your Japanese reading skills further, the Japanese original, almost a different book, really, is also available: 『神道 日本生まれの宗教システム』 ISBN: 4-7885-0658-0.
Have you come across the books of Brian Daizen Victoria?. They are Zen at Wa
r and Zen War Stories
and contain much interesting information about how Buddhism ardently assisted the Japanese war effort. Chapter 11 of the latter book ("Buddhism: A Top Secret Religion in Wartime Japan") is an exposition of the role that Japanese
Buddhism was expected to play in the war effort.
As an aside, after noting that you mentioned both the commingling of Buddhism and Shinto and the long held view, and relatively recent action taken from it, that Buddhism is a foreign religion, I will mention the following:
While Buddhism is often times seen and treated as a foreign religion, at the same time, there are large factions of the Japanese Buddhist "Ecclesiastical" hierarchy that hold to the view that there is something so innately Japanese about THEIR Buddhism that a non-Japanese should not, or cannot, be brought "into the fold." Obviously, not all hold to this view, but it is still pervasive.
I just thought that I'd point out the paradox, or hypocrisy, depending upon one's view as it seems to apply to the root topic of Aikido. (Is Aikido Universal? Is Aikido parochially Japanese? Is there some paradox at work? Is there some hypocrisy? Perhaps there is, as I suspect some Japanese Buddhists believe, an Outer Aikido (Non-Japanese) and an Inner Aikido (Japanese).
Well now I'm getting late!