>We also might just see a gradual escalation of low-intensity conflict rather than a single breakout event
Because Western societies (and those heavily influenced by them) are weird. They act like frogs in a pot in that they don't notice as you turn up the heat. However, unlike frogs, generally social structure/hierarchy breaks down much faster the closer to death these sorts become. This is usually sounded off initially by capital flight, followed by scandals/government corruption or demographical tensions that get out of hand, and then finally civil war. That is, the up-until 130(Freedom) or so frogs suddenly and all at once get the hint that they need to get the fuck out of whatever's boiling them and they flee in any and every direction. Sometimes only a few of the frogs get out before the lid is put on (events like the burning of the library of Alexandria or a theoretical war between first world nations and obviously the repercussions for at least the rest of our lives
), and sometimes most of the frogs get out (Utah surrendering to the USA, saving America a war that would have absolutely decimated their military at the hands of the Mormons because their church leaders asked them not to fuck up again like the completely justified
Indian genocides) and maybe the gas hiccups on the boiler turning off the heat and saving the frogs (most of the modern wars started and things that should have been breaking points being ignored or fixed at the last second or something miraculously preventing the disaster). Unfortunately, whoever wants those frogs boiled is making damn sure to keep the heat on, but ain't putting the lid on because they don't want to babysit.