Why was World War 2 both the allies and axis powers fault?

World War II can be seen as a failure of both the Allies and Axis powers due to their aggressive actions and political decisions. The Axis powers, particularly Nazi Germany and Imperial Japan, pursued expansionist policies and military aggression, leading to widespread conflict. Meanwhile, the Allies, especially in the interwar period, adopted policies of appeasement and isolationism that allowed these aggressions to escalate unchecked. Ultimately, a combination of failed diplomacy, ideological extremism, and nationalistic ambitions on both sides contributed to the outbreak of the war.