I thought it would be implied that I’m speaking about modern times. The economic system is the msin driver in large societies, though. In Europe, prior to capitalism, the primary determinant was feudal interests.
Chimps don’t have war. They fight, but is every skirmish a war? Wars come from creating and wielding armies.
Capitalism is the primary driver of wars, it determines the basic structure of what is and is not permissible, generates nation-states (these did not always exist, actually), and then creates the conditions by which the national bourgeoisie nation-states push for war in order to become international bourgeoisie (imperialists).
For example, the US keeps the middle east in a regular state of war to prevent them from having independent policies regarding oil. It is concerned about oil because of the petrodollar. It is concerned about the petrodollar because it is th3 primary financial war instrument by which it jeeps other countries sending superprofits its way and otherwise screwing with countries using interest rates. And it does those things because the US is the global seat of capital, it is where the big finance companies are based.
How many wars have there been in the middle east since 2000? How has the US been involved? Do they just do it for the thrill of domination?
Do you think the USSR and Eastern Europe were free from the tendencies of capitalism to create imperialist war? The only post-WWII wars in Eastern Europe were skirmishes by capitalist-funded nationalists (quasi-fascists) and the civil war in Yugoslavia exacerbated by NATO to balkanize the country. The wars that the USSR supported were all pre-existing national liberation movements against imperialist colonizers, and they nearly always entered after imperialists had thrown massive resources into oppression. For example, Vietnam.