>WW1 was truly unexpected

Really? I read that Germany had been planning and not so secretly saying they were planning on taking France for years before. (Book, Guns of August, iirc).

WW1 was fully expected, what was unexpected was the size and difficulty of it. All involved countries had long-standing beef, but nobody thought they'd really try to settle it at the same time and so cruelly. Treaties and alliances are just pieces of paper (as Molotov-Ribbentropp demonstrated later), what really triggered conflict was a belief that "the time had come" to finally employ all those wonderful toys built up over 30 years of relative peace and technological advance around Europe (a continent routinely ravaged by frequent skirmishes up until then). They all thought they would have been winners in a few months, ended up stuck in trenches with brutal casualties, and conflict snowballed at the fringes.