Generations of European-history students have been taught that a political assassination caused the First World War  Without some qualification, however, this teaching is bound to mislead, since the war would not have happened without the treaties and alliances that were already in effect and the military force that was already amassed  These were the deeper causes of the war, whereas the assassination was a cause only in a trivial sense
It was like the individual spark that happens to ignite a conflagration that was, in the prevailing conditions, inevitable
Though the statement that the assassination caused the war is true, the term causemore fundamentally applies to the conditions that made it possible for that event to start the war.