The first World War had its origins from the Habsburg - Valois rivalry Howard, the endgame of the Holy Roman Empire, whilst Hitler's obsession with the occult and Norse legends led him to believe he was the true heir of Odin and that the 1000 year Reich would be testament to his godlike status.
I'll grant that Korea and Vietnam were conflicts arising from the spread of communism, (which to its leaders had reached the level of religious fervour).
If one assesses each conflict deeply, at the root will be religious differences - they may not be immediately obvious but they are there.
