WWIII was never going to be triggered by a single event, but many culminating events that wouldn't be recognized until it was obvious in hindsight.
The unofficial American state in the middle east, israel, struck a blow against the iranian people at a time when they felt they had the most control over the narrative, and the world's media took the bait. They exclaimed that israel, who was once the victim, was justified in their actions. They waged war with palestine, iran, lebanon. Then it seemed all at once further war broke out. China, emboldened by the brash actions of russia and israel, launched it's first tactical strike on the government centers of taiwan, avoiding an all out conflict, but effectively eliminating most of the small nation's leaders.
Many nation states were furious at the loss of chip manufacturing and the risk that posed to their nation's future, a new group of countries excluding the united states formed, with the intent to exert force against the nations causing suffering. Unfortunately it wouldn't last more than a week as immediate retribution in the form of drone strikes... blah blah blah
Long story short, every escalation of every conflict will perhaps eventually be looked at as simple math adding up to a worldwide conflict. One cannot fight violence with inaction, neither can it be stopped permanently with violence. Fear has been the largest thing stopping nations across eurasia from getting embroiled in an even larger conflict.
Make no mistake, this war has already begun, the people grow restless and we have internationally stopped fearing nuclear weapons. War is our ultimate collective evil, and it's been our ugly companion for our species' whole existence.
May some of us find and cherish peace, and empathize with those who have had that choice taken from them.