spent more than $ 4 trillion or 36% of its GDP.More than 400,000 U.S. troops were killed in the defeat to defeat Nazi Germany, Italy and Japanese Empire.
$4 trillion Though it lasted fewer than four years, World War II was the most expensive war in United States history. Adjusted for inflation to today's dollars, the war cost over $4 trillion and in 1945, the war's last year, defense spending comprised about 40% of gross domestic product (GDP).
