Why humans want to wage wars starts with an amusingly ironic quote:
Perhaps the most famous last words in military history were uttered by an American Civil War officer, John Sedgwick: “They couldn’t hit an elephant at this distance.” He was immediately killed by enemy fire at the battle of Spotsylvania in May 1864.The comment illustrates a problem identified by behavioural scientists that dominates the psychology of warfare: a strong universal tendency to underestimate the enemy’s strength, while overestimating your own side’s capacity.
This positive illusion “increases the chances of successfully bluffing the enemy into believing he cannot or is unlikely to win, and so it also increases the unpredictability of wars.”