- Failure of the Schlieffen Plan: Germany's initial strategy of a rapid march through Belgium and France was unrealistic and led to a protracted conflict.
- Underestimating the Russian military: Germany's belief that Russia would be quickly defeated proved incorrect, resulting in a two-front war.
- Failure to adapt to trench warfare: Both sides struggled to adapt their tactics to the realities of trench warfare, leading to unnecessary casualties.
World War II:
- Underestimating the Soviet Union: Germany's invasion of the Soviet Union was based on the assumption of a quick victory, but the Soviets proved capable of mounting a fierce resistance.
- Pearl Harbor attack: The United States' failure to anticipate and prevent the Japanese attack on Pearl Harbor led to a significant loss of life and damage.
- Ignoring strategic intelligence: Both sides failed to adequately use intelligence, such as the Enigma decrypts and decoded Japanese messages, which could have provided significant advantages.
Vietnam War:
- Escalating involvement: The United States gradually increased its involvement without a clear strategy or exit plan, leading to a prolonged and costly conflict.
- Underestimating the North Vietnamese: The United States initially underestimated the strength and resilience of the North Vietnamese forces and their ability to wage guerrilla warfare.
Other notable mistakes:
- Maginot Line: France's reliance on the Maginot Line, a system of fortifications along its border with Germany, proved insufficient in preventing German advances.
- Bay of Pigs Invasion: The United States' failed attempt to overthrow Fidel Castro in Cuba in 1961 resulted in a humiliating setback.
- Rwandan Genocide: The international community's failure to intervene effectively allowed for the systematic killing of hundreds of thousands of people in 1994.
These historical examples highlight how miscalculations, strategic blunders, and misjudgments have significant consequences in wartime and can profoundly affect the course of events.