“Unintended consequences” in History

What would by some be named the American Civil War, most believed would end in a few months…

Those on all sides going to war in 1914 believed they would be home by Christmas…

Certainly, the English would not finally declare war on Hitler’s Germany with the invasion of another country Poland… The Wehrmacht would take Moscow before needing winter gear…

Certainly Moscow would rule Kyiv within a week or two after February 24, 2022…