Kaisar Wilhelm ( because of his birth damaged arm and what THAT did to his personality from there on ) had a "thing" about besting his Brit first cousin and the British Empire. His arrogance and inferiority complex brought him to jealous rages.
Emperor Franz Joseph, of the Austro-Hungarian Empire, lost his heir and ONLY son through Rudolf's murder and suicide pack with his mistress, leaving the Austro-Hungarian Empire with no direct blood heir, since Franz-Joseph and Elizabeth ( the world renown beauty "Sissi" ) only had three children; only one of them a son.
So that left the Emperor making his nephew, Franz Ferdinand and his Morganatic wife the heir apparent/future Emperor and Empress...with NO future heirs after them.
Franz Ferdinand, like his now dead first cousin, Rudolph, was more enlightened and not as rigid as his uncle, so would have made a pretty good Emperor....if the damned lefty , Nihilistic youths, the BLACK HAND, and some Russian higher ups hadn't planned, carried out, and/or funded his assassination!
Franz Joseph asked Wilhem to help him get an apology.If that had worked out, there would have been NO WW I! And as we know, it didn't, through no fault of Kaiser Wilhem.
President Wilson was a lot of things...a huge racist, supporter of the KKK, a lefty, very naive, and also an IDIOT !The French ( Clemenceaue )and Brits ( Lloyd George ) at Versaille had him by the nose, did whatever THEY wanted, which he signed off on and the Treaty of Versaille brought forth ALL of the wars of the 20th century AND the spread of Communism and the birth of Fascism and Nazism.
Yes, the above is rather simplified, but also FACTUAL!
All that European Royal intrigue was why our Founding Fathers, President Monroe, etc., wanted us to stay out of any messes over there. All those wars, and for what ? Destroying some of the most beautiful cities and towns on the planet and quite probably we lost our best and brightest to these wars, and look what’s left today.