Let's say that, in Sept 1913, the city of Vienna, along with everyone in it at the time- including Adolf Hitler, Josef Stalin, Josip Broz Tito, Vladimir Lenin, Leon Trotsky, Albert Einstein, Sigmund Freud, Ernst Schrodinger, Peter Altenberg, Theodor Herzl, Alfred Adler, Adolf Loos and many more- gets ISOTed away to a virgin Earth, effectively vanishing without a trace to be replaced by pristine, uninhabited wilderness. How much of an impact would this ISOT have had; how much would you expect events in this ATL, left behind in the aftermath of Vienna effectively being vanishing from existence, to diverge from OTL, and how? And meanwhile, on the virgin Earth they got ISOTed to, how do you envision that the city of Vienna, and everyone in it, might cope with their situation, with the entirety of an otherwise uninhabited Earth all to themselves?