Counterfactuals “are often claimed to open up the past by demonstrating the myriad possibilities, thus freeing history from the straitjacket of determinism and restoring agency to the people. But in fact they imprison the past in an even tighter web: one tiny change in the timeline – Archduke Franz Ferdinand escapes assassination in Sarajevo, the British cabinet decides not to enter the war – leads inevitably to a whole series of much larger changes, sometimes stretching over decades almost up to the present day. Yet this ignores, of course, an infinite number of chances that might have deflected the predicted course of events along the way – Franz Ferdinand might have fallen victim to another assassin’s bullet, or died in a hunting accident; Britain might have entered the war later on; the US might have come into the conflict on the side of the French; Austria-Hungary might have collapsed in the face of nationalist revolts; and so on.”
See also: What if . . . ? Konstanz Collaborative Research Group.