* The scale of the war. World War II was the largest war in history, involving over 100 million people from more than 30 countries. The fighting took place on every continent except Antarctica, and it lasted for six years.
* The use of new technologies. World War II saw the development and use of new weapons and technologies that were more deadly than anything that had been seen before. These included the atomic bomb, the rocket, and the submarine.
* The civilian toll. World War II was the first war in which civilians were deliberately targeted by military forces. This was due in part to the rise of totalitarianism, which led to the creation of regimes that were willing to sacrifice their own people in order to achieve their goals.
* The aftermath of the war. The war left behind a legacy of death and destruction that lasted for years. Millions of people were displaced from their homes, and many died from starvation and disease. The war also led to the Cold War, which lasted for over 40 years and kept the world on the brink of nuclear war.
Here are some specific examples of how the factors listed above contributed to the high death toll in World War II:
* The atomic bombs: The atomic bombs that were dropped on Hiroshima and Nagasaki killed hundreds of thousands of people instantly. The bombs also caused long-term health problems for many survivors, who died from cancer and other diseases.
* The Holocaust: The Holocaust was the genocide of six million Jews by the Nazi regime. The Jews were killed in gas chambers, concentration camps, and other places. The Holocaust was one of the most horrific events in human history.
* The Battle of Stalingrad: The Battle of Stalingrad was one of the bloodiest battles in history. Over two million people were killed in the fighting, which lasted for six months.
* The Bengal Famine: The Bengal Famine was a man-made famine that occurred in Bengal, India, in 1943. The famine was caused by the British colonial government's decision to divert food supplies to the war effort. Over three million people died in the famine.
World War II was a truly global conflict that had a devastating impact on the world. The war left behind a legacy of death and destruction that still resonates today.