The major difference being that the Germans and Japanese were living in the 20th century. Not the 7th or 8th. The Nazis were what they were in spite of Germans being Christians. In Japan the God-Emperor helped a lot withe the "pacification". If he had not, things could have been very ugly for a very long time.
Modern Islam, at least the variety which spawns suicidal terrorists, has imbibed a good deal of 20th century though: Sayed Qutb, the philosophical inspiration for the Egyptian Islamic Brotherhoods from which all of the suicidal terrorist organizations take their root was heavily influenced by existentialism. It is his idea that self-destruction in jihad is a sign of absolute commitment to Allah (absolute commitment being the only source of value in extistentialism) that is the basis for modifying the classical Islamic notion of martyrdom (which included only death in battle against the infidels as well as deaths of sorts recognizable to Christians as martyrdoms) and the classical understanding of suicide so that suicide bombings, crashing planes to kill infidels and the like was no longer regarded as haram.
Likewise the philosophical underpinnings of both Naziism and the Japanese Imperial Emperor cult were bound up with a romanticization of on the one hand Teutonic paganism and on the other pre-Shogunate Japan and pre-Buddhist Japanese religion.
All three movements very much want(ed) very much to turn back the clock to a fantasized golden age, all three are equally antithetical to modernity while at the same time drawing strength from it.