So this is the argument that there's a path dependence in how peaceful a civilisation is. I think whatisalthist argued this as well - that Christianity (with largely pacifist founders) did a lot to moderate Rome, and then the Catholic Church (which some argue is the rump of the Roman empire) moderated its region of influence.

whatifalthist is a bit western centric (and a bit ... odd and extreme in some ways), but it seems reasonable, you could argue that India and China are also historically pretty peaceful (more so even than Europe), internal issues aside (yeah, Taiping rebellion, the 1940s and 50s, and any other Chinese civil conflict for example). 2 nuclear powers with the ability to rapidly create well over a million strong armies (India and China) can be having actual deaths on a contested border (e.g. the 2020 border clash) and it's no real concern, whereas in some regions a war can basically start over a mean tweet. The argument is that culture / institutions / path dependence matters.