To fail to recognize WWII was a holy war, is to fail to see what is happening now.
To the Nazis it certainly was. And it became that way for everyone towards the end. The entire 1900s were a time of religious warfare between fanatical supporters of various nations and ideologies.
Any ancient Athenian would instantly recognize, say, the American Eagle as the local equivalent of Athena. Which is fine, people need group identities to cooperate effectively, and these group identities will inevitably end up having recognizable personalities. But we'd gain more control over the outcome if we'd acknowledge that nations, ideologies, and anything else that can command people's loyalty is functionally a god and thus follows mythological, rather than rational, patterns.
Currently people aren't really aware of these high-level structures, which is why trying to control or even predict the outcome of various situations is a bit like decompiling a highly optimized program. And often the result ends up simply repeating typical religious patterns, for example with current efforts in Europe to placate the angry god Invisible Hand with public sacrifices - or "austerity", as the clerical cast ("economists") like to call it - to get back economical prosperity. And of course, communists on the other side of the ideological divide insisted that their god should bring forth a paradise on Earth, if only doctrinal purity was maintained. Evidence mattered little, until people finally lost their faith, at which point the Soviet Union fell pretty much overnight.
A god is a superorganism typical for humanity, the equivalent of anthill or beehive, thus every war is a holy war - a clash between rival deities - no matter what its nominal cause. Every member of a particular society has its image in their mind, suggesting courses of action compatible with said society, which then serve to reinforce them in anyone witnessing these actions. All too often that image has been quite beastly, but with greater awareness of these mechanisms, one can exert conscious control over the image - take actions which project the image one wants, hopefully starting a chain reaction that perpetuates the updated image through the entire society. It's about time we take human destiny into human hands under conscious control, rather than leave it to luck and instincts that have outlived their usefulness.