Doshu although he did not participate in military action did have first hand experience of the effects of the war through the bombing of Tokyo. I do think witnessing the acts and atrocities of war as a bystander vs being on enemy territory with sights set on you and your sight on the enemy are different. Your duty in this foreign land is to kill the enemy by any means necessary and try not to be killed in the process. It is a hard thing to process for me since I have not been in the military or had to experience anything like the atrocities of war.
I live in Hiroshima and I think I do not need to spell out the emphasis laid here on the atomic bombing of Hiroshima as a unique act of war. There are still living A-Bomb victims here, some of whom I know. The distinction you make, between 'witnessing the atrocities of war as a bystander vs being on enemy territory with sights set on you' was probably clearer to the Japanese in the Russo-Japanese War than it was in World War II. The Japanese at home had a romantic notion of being involved in the siege of Port Arthur, which is why General Nogi was hailed as a war hero afterwards, even though he was responsible for sending thousands of young soldiers to their deaths. All the stuff about 'fighting spirit' was propaganda, designed to divert attention from the poor equipment, lack of ammunition and poor training. At least Morihei Ueshiba was in a position to creep up at night, with a sword, rather than face a machine gun barrage, also with a sword, in the daytime and in full view of the enemy, which is what many of his subordinates were ordered to do.
One factor in making your distinction less clear in the case of World War II, is that in 1945 the Japanese population was much more conscious of being participants, civilian combatants if you like, preparing for an allied invasion of Japan. And, yes, there was the fire bombing of many Japanese cities and I believe the fire-bombing of Tokyo in March 1945 caused as many deaths as the atomic bombing of Hiroshima in August. And the deaths were caused, not by an emeny solider with a machine gun, or a sniper with a rifle, whom you can't see but you suspect is there, but by an enemy pilot, high in the sky, whom you can't see but you also suspect is there (though in the case of Hiroshima, this was not so clear). For the unlucky ones, the results were the same, however.