Jung lived in a time of crisis. He was confronted with the atrocities of two world wars, spent his final years in the climate of the cold war, and was hugely concerned about mankind’s inability to find solutions to the recurring occurrences of mass conflict he was forced to witness in his lifetime. It should come as no surprise, then, that Jung wrote extensively about the possible causes of war and conflict. A central notion which he defended throughout his career was that the roots of war are to be found in the human psyche, in what he called our “war-like instincts,” which we will never be able to eradicate:
"Anything that disappears from your psychological inventory is apt to turn up in the guise of a hostile neighbor, who will inevitably arouse your anger and make you aggressive. It is surely better to know that your worst enemy is right there in your own heart. Man‘s war-like instincts are ineradicable – therefore a state of perfect peace is unthinkable..."