alt Hacker News> The source of these conflicts is always material. Always.
Since the beginning of the Green Revolution¹, no. The source of these conflicts are always ideological. Always. Ideology may come through religion or some other medium.
Countries don't go occupying land because they need crops or slaves anymore. Material is always cheaper to buy than to get from an occupation. The desire to annex some land is always for somebody's pet project, it doesn't make economic sense.
1 - In a very wide sense. Agriculture stopped being the bottleneck for human populations at some point in the 18th or early 19th centuries.
Religion is a subset of ideology, and both are a mechanism to recruit labor to fight and not the reason for conflict. Material isn't cheaper to buy, the "owner" of the material has all of the leverage - lock them in like a SaaS contract and them jump the price up, and the buyer can't do anything. Crops and slaves are no longer valuable as port worthy coast and natural resource deposits, but the fight is still over land and power.