The idea that my gov't is totally in control at all times and willing to do evil things is more comforting than the idea that geopolitics is actually chaos, and a few motivated individuals can decide to murder the president or coordinate an attack on citizens to inspire a 20 year war.
And it's one of those opinions that (IMHO) is hard to hold for someone with sufficient history training.
The murder of one archduke kicked off a world war. Of course the action of one person in the worst place at the worst time can precipitate unspeakable horror. It's happened before.
Now, I don't know shit about shit, but from what I've tried to read on the subject, a nascent German empire after the Franco-Prussian war was ready to demand its place at the grown up table of France, England, and Russia for years.
So no, not just a single moment of bad luck turning friends into enemies.
I have no idea why you are getting downvoted.. but people cannot deal with chaos or "shit happens for no reason". People seek purpose and when none exists, make up one.