On this Memorial Day, I found an interesting video on the causes of World War II. They argue that, if anything, WW II was more about access to food than anything else.
(the video is at https://youtu.be/... if the embedding didn't work, which hasn't been for me).
As I think about it, most wars over the last century have been about access to resources, be it food, oil (as in the case of both Gulf Wars) or land (which is the cause of the Israeli-Palestinian conflict, not religion as many on the religious right believe). The other primary causes for war over the last century have been nationalistic wars either by a ethnic group fighting against an oppressive, distant imperial force or the result of poorly drawn lines on a map (the wars in the former Yugoslavia during the 1990's comes to mind). I submit this is why the cold war kept from becoming a hot war. Both sides were economically self-sufficient to where they never felt they had to invade the other person's territories, and were able to use localized nationalism to sustain the proxy wars, either in southeast Asia or Central America.
