This article was written with the assistance of A.I. technology, and has been edited and fact-checked by Melly Alazraki.

More than 100 million troops were mobilized during World War II, hailing from over 50 countries. The deadliest conflict in human history, more than 60 million people were killed, including 6 million Jews who were systematically murdered by the Nazi regime in concentration and extermination camps.

Like in World War I, the Soviet Union, one of the Allied powers, mobilized the most troops at approximately 34.7 million, according to data compiled by Statista. The troops comprised 31.8% of the country’s population at the time, also the highest share of any major power, Allied or Axis. The Soviet Union also suffered the most deaths of any country, with an estimated 10.7 million military and 12.5 civilian deaths.

The impact of WWII on geopolitics and international relations is still evident today. The war led to the decline of the British Empire and the rise of the United States and the Soviet Union as the world’s superpowers. The war also resulted in the creation of the United Nations and laid the groundwork for the Cold War and the NATO alliance.

Click here to see the nations that mobilized the most troops during WWII.