World War II was the deadliest and most destructive conflict in human history. Beginning with Germany’s invasion of Poland in September 1939 and ending with Japan’s surrender six years later, the war spanned three continents and left as many as 60 million people dead by some estimates. Though the war ended nearly 80 years ago, its impact on geopolitics and international relations remain evident today.
Between the more than 50 countries that were actively engaged in the fighting, over 100 million troops were deployed throughout the conflict, according to the National WWII Museum. In some cases, leading military powers enlisted the equivalent of over 20% of their total population.
Using data compiled by Statista, 24/7 Wall St. identified the biggest armies in World War II. Countries are ranked by the total estimated number of troops mobilized during the war. We only considered the 22 countries with available data that mobilized over 200,000 troops.
Though the United States did not officially join the war until Japan bombed Pearl Harbor, about two years after Germany invaded Poland, the American war effort ramped up quickly. Not only did the U.S. put its industrial might into mass weapons and material production, it also mobilized an estimated 16.4 million troops, more than all countries but Germany and Russia, which mobilized 18.1 million and 34.7 million troops, respectively. (Here is a look at the countries with the 20 strongest militaries.)
In the European Theater, fighting between Germany and Russia on the Eastern Front was especially devastating. The attempted German invasion of Russia, known as Operation Barbarossa, resulted in some of the deadliest battles and sieges in history. Partially as a result, no country suffered more deaths – both civilian and military deaths – than Russia during the war. More than 23 million Russians are estimated to have been killed in WWII. For context, American deaths are estimated to have totaled less than half a million. (Here is a look at the most devastating battles in recent history.)
Click here to see the nations that mobilized the most troops during WWII.
Click here to read our detailed methodology.
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