There is a great netflix documentary made in 2018 called "the long road to war". By the time the shooting happened a lot of other pieces had fallen into place. Basically, there were people in military circles and in the government that dictated the geoplitics game based on which country has leverage, who has the train tracks or a port to handle the logistics of war, and there was a certain zeitgeist, an egregore if you will, and things were ripe for conflict.