World War 2 was a global conflict that took place from 1939 to 1945. It involved major world powers and their alliances, resulting in widespread devastation and significant geopolitical changes. The war began with the German invasion of Poland and ended with the dropping of atomic bombs on Hiroshima and Nagasaki, marking the start of the atomic age. 

Introduction to World War 2

• ??World War II: Global military conflict (1939 to 1945). Involved major world powers - Allied forces (led by the United States, Soviet Union, and United Kingdom) and Axis powers (led by Nazi Germany, Italy, and Japan). 
• USA Entry: Japan’s surprise attack on Pearl Harbor brought America into World War II in December 1941.
• Result: Allied powers won the War. The U.S. dropped atomic bombs on Hiroshima and Nagasaki in August 1945, and Japan's formal surrender formally ended the war.

Causes of World War 2

• Treaty of Versailles: The harsh terms imposed on Germany after World War I, including massive reparations and territorial losses, created resentment and economic instability.
• Rise of Fascism: The ideologies of Adolf Hitler's Nazi Germany and Benito Mussolini's Italy promoted ultranationalism, militarism, and expansionist ambitions.
• Failure of Appeasement: The policy of appeasing aggressive actions of Germany and Japan by the Allied powers, such as the Munich Agreement, only emboldened their aggression.
• Failure of the League of Nations: The ineffectiveness of the League of Nations in preventing and resolving conflicts contributed to the erosion of international order.
• Economic Depression: The Great Depression of the 1930s led to economic hardships and political instability, which fueled support for extremist ideologies.
• Imperialism and Colonialism: Rivalries over colonial territories and resources, particularly in Asia and Africa, intensified global tensions.

Impact of World War 2

• Loss of Lives: The war resulted in the death of an estimated 70-85 million people, including both military personnel and civilians, making it the deadliest conflict in human history.
• Holocaust and Genocide: The systematic persecution and genocide of six million Jews by Nazi Germany during the Holocaust remains one of the darkest chapters in human history.
• Emergence of Superpowers: The United States and the Soviet Union emerged as the two dominant superpowers, shaping the post-war global order and sparking the Cold War.
• Decolonization: The war weakened European colonial powers, leading to the dismantling of many colonial empires and the emergence of independent nations.
• Formation of the United Nations: The failure of the League of Nations prompted the establishment of the United Nations, aiming to prevent future conflicts and promote international cooperation.
• Cold War and Division of Europe: The ideological and political divide between the capitalist West, led by the United States, and the communist East, led by the Soviet Union. 
• Technological Advances: World War II saw significant advancements in military technology, including nuclear weapons, radar, jet propulsion, and computers etc.
• Human Rights and International Law: The war's atrocities and the Nuremberg Trials brought attention to the need for international human rights standards.
• Economic Transformation: The war stimulated industrial production, technological innovation, and economic growth, paving the way for the post-war economic recovery.

Conclusion

World War II resulted in the extension of the Soviet Union’s power to nations of eastern Europe and marked the decisive shift of power in the world away from the states of western Europe and toward the United States and the Soviet Union.