Agree with your layout. Autro-Hungarian Empire’s intransigence when Serbia responded to all but one of her demands is what lit the fuse. The Empire was not remotely prepared for a war with even little Serbia, but pulled everyone into it with entangling alliances.
Thank you, Gentlemen. You pointed out the “little open secret” of the origins of WW 1 correctly :-)
However; I beg to differ on the question of how old Germany is: the German people was first mentioned by Tacitus in “Germania” around 95 A.D.
The Germanic tribes becoming a united realm did however evolve in the late 10th, 11th and early 12th centuries under the Ottonian and Salic Emperors, after the old Frankish empire - which had encompassed present-day France, Netherlands, Belgium, Luxemburg, Switzerland, Western Germany and northern Italy (last but not least) - had fallen apart in the late 9th century.
BTW, the French kingdom evolved just at roughy the same time, between the late 9th century and the final French victory over the Angevin Empire in 1214.
Only the Kingdom of England was somewhat faster in seeing the light of day - but then no-one on the Continent had somebody like the Venerable Bede, who invented the term “England”, using it first in his “Ecclesiastical history of the English People”.
Although it took until 937 for England to become a single kingdom, the term “English” as an idea, then as an ethnolinguistic and cultural term, had been coined more than two centuries earlier - by the aforementioned sagacious monk of Jarrow :-)