Prior to the destruction of Core as a civilization, it functioned as a hate sink for every nation of the world, being more more or less something everyone agreed on needed to go and thus taking attention off of local rivalries. With the absence of Core, nations started turning on each other as their squabbled turned closer to home, leading to wars being declared on neighbors. I was not directly affected of course, my own corner of the map populated by only myself and stray barbarians (thanks to the earlier Musketeers), but where before the Great Fairy Kingdom was BBFs with everyone, now we had to actually pick sides as people demanded the strongest military in the world (points wise, techwise a kingdom heavy swordsman was in a tough position on the field, though promotions helped close the gap somewhat) aid them.
At first, I did the sensible thing and politely declined as I continued to build up my forces and explore the world while everyone was busy killing each other, but eventually that led to a new issue as the Hitties, who were stable from guards I sold them literal millenia ago, began to conquer their neighbours, first vassalizing America, completely absorbing the minor nation of Brazil, and then turning their sights to California. They were gaining more points on the scoreboard than myself, and something needed to be done about it, but at the time my military, combined with the pain in the ass sea travel was was not really up to a trans-continental war.
The war expanded into the World War as the Hitties were used as an excuse for Germany to declare war on the Pirates and the Pirates to declare war on Germany and the Portuguese declaring war on both and the Mongols stuck on a tiny island declaring war on... someone, IDK they couldn't really do anything anyways, and territories were changing left and right.