WWII GROUP is a term used to refer to the four major groups of countries that were involved in World War II. The AXIS was a coalition of countries led by Nazi Germany, Italy, and Japan. The GIs were the American soldiers who fought in the war. The WACs were the Women's Army Corps, a branch of the United States Army that was made up of female volunteers. The WACS were the Women's Auxiliary Corps, a British organization that provided support to the military.