Can you say Imperialism and Nationalism?
Well, doubtless nationalism was a precondition for a war of nations, but I am not sure that’s an adequate cause in itself. I’m even less certain imperialism had much of an effect, except, I suppose, the rather weak, slow-motion imperialism Austria was conducting in the Balkans.
Certainly, though, it could be said the Alsace and Lorraine were the objects of nationalistic ambitions on the part of France. But since Elsass und Lothringen (Alsace and Lorraine) were actually German speaking places, indistinguishable from the people on the other side of the Rhine, French ambitions to reclaim them could be considered imperialist in a way. Could be said of Germany as well; Nationalism while in occupation of Elsass und Lothirngen, imperialism in 1870. German designs on Russian territory were not evident; even less Russian designs on German territory. Germany’s non-European territories were negligible. Russia’s (except for largely uninhabited Siberia, Central Asia and the Russian Far East, which were uncontested) and Austria’s were none. So I don’t know that non-European territorial ambitions had much to do with it, though some believe the German naval buildup and the Kaiser’s stupid ride into Agadir might have made England desirous of sinking Germany’s ships.
I am one of those who believe that France’s Plan 17 was fundamentally an aggressive strategy that France might have hazarded sooner or later over Alsace and Lorraine. But France was much less of an industrial power and had a substantially smaller population than Germany, so that could reasonably be doubted. Germany itself had nothing to gain in WWI.
It’s interesting to fantasize different outcomes in history. Had the Kaiser and the Hapsburg emperor decided to unite the crowns with a diplomatic marriage, giving Hungary a “rotation” in the system like the one among the princely families in Imperial Japan, the union would have been unassailable by any, needing nothing from any. England would have felt isolated, as England often does, and likely would have gotten closer to the U.S. (everyone on both sides of the Atlantic knew that was inevitable anyway) France could have dreamed its revanchist dreams and those of La Gloire over many bottles of excellent wine. Croatia would have become ever more integrated into the Empire. Germany/Austria could have given Russia the “green light” to retake Constantinople, the ancient Russian dream, (and that of all Orthodoxy) and be the indisputable leader of the Orthodox world. Europe would have been redivided (except for part of hapless Poland, which had been divided in three) along the ancient “Latin/Orthodox” line, which took another hundred years, nearly, to reestablish after WWI. Japan would never have taken the Kwantung Peninsula, which was its later springboard into China, and would not have dared challenge Germany for it, an undistracted France for Indochina or an undamaged England, allied to the U.S., for anything. Nationalism, which became so toxic under Hitler and, indeed, under Stalin and Japan, would have had to take a back seat within the polyglot empires on both sides of the Latin/Orthodox line, England and France could have played imperialism out to their terminations in a more peaceful way and given more time to formulate better institutions worldwide, the tatterdemalion Ottoman Empire could have gone back to sleep after the Russian seizure of Constantinople, both Hagia Sophia and the Blue Mosque would have resounded with Orthodox hymns in both Greek and Slavonic round the clock, and the world might well have enjoyed a century of prosperous peace.
Lenin would have had to be a schoolteacher with unlikely dreams. Hitler could have been a perpetual vagabond on the edge of insanity. Stalin could have had a fair life for a time as the bank robber he was otherwise born to be, Hirohito could have grubbed for worms in Tokyo Bay decades earlier, and millions would have survived that did not survive.