"In his System of Subjective Public Laws, published in 1892, the Austrian public lawyer Georg Jellinek analysed what he called ‘the normative power of the factual’. By this he meant the tendency among human beings to assign normative authority to actually existing states of affairs. Human beings do this, he argued, because their perceptions of states of affairs are shaped by the forces exerted by those states of affairs. Trapped in this hermeneutic circularity, humans tend to gravitate quickly from the observation of what exists to the presumption that an existing state of affairs is normal and thus must embody a certain ethical necessity. When upheavals or disruptions occur, they quickly adapt to the new circumstances, assigning to them the same normative quality they had perceived in the prior order of things.
Something broadly analogous happens when we contemplate historical events, especially catastrophic ones like the First World War. Once they occur, they impose on us (or seem to do so) a sense of their necessity. This is a process that unfolds at many levels. We see it in the letters, speeches and memoirs of the key protagonists, who are quick to emphasize that there was no alternative to the path taken, that the war was ‘inevitable’ and thus beyond the power of anyone to prevent. These narratives of inevitability take many different forms – they may merely attribute responsibility to other states or actors, they may ascribe to the system itself a propensity to generate war, independently of the will of individual actors, or they may appeal to the impersonal forces of History or Fate."
[op. cit., pp. 361-362]