Every major conflict from the past has started in the same way and the world is heading down that road right now.
Since the Second World War there have been four... I think?
Korea: Syngman Rhee reckoned he was going to invade North Korea. Next thing he knew a ruck of North Korean tanks were sitting in his front garden. Well the N. Koreans probably thought he was being serious rather than trapping off. Then it degenerated into a proxy war between USSR and USA(UN) with Douglas MacArthur wanting to nuke the north.
VietNam: Started when the French thought they were going to move back into their old colonial powers in Indo China after the Jpas were evited in 1945/6. Ho stuck it up the French at Dien Bien Phu but the elections promised at the Geneva Accords were never held and the USA with its Domino Theory in full sway supported a couple of bandits running the show in the south. Remember the self immolation of a buddhist monk in protest ?
Ultimately Ho stuck it up the yanks in 1974 at the end of a sort of proxy war where the yanks fought but the USSR pumped in materiel through China.
Middle East: Which bit? Israel v Arabs ?. Well being neighbours with a bunch who have vowed to drive you into the sea can't be easy and concentrates the mind.
The bit where we supported Iraq when it was fighting Iran or the mess that has now been created ?.
Balkans: As soon as Tito turned his toes up and his boot heel came off the neck of the trouble makers ...bang we left the 20th century as we had entered it....approximatively
There
is a bit of common thread running through there though.