World War II Japan's wars of aggression and conquest began long before the fascist takeover of the 1930s and the alliance with Nazi Germany in 1940, and the idea that the Japanese were a superior race also had a long pedigree -- as indeed did the Nordic-Aryan racism of the Nazis. Both used the tactics of blitzkrieg and surprise to end up in control of most of Europe and Asia by 1942, before the tide began to turn against them at the battles of Midway and Stalingrad. In 1940 the U.S. armed forces were smaller than those of Belgium and Romania, grew to eleven million by 1944, and became a far more formidable force than the Germans, Japanese, British or Russians would have imagined at the outset. The U.S. military very quickly overcame the deficiencies in training, command and effectiveness it had shown in the early battles like Kasserine Pass and were well-prepared to defeat the Wehrmacht by the time of the Normandy invasion. German combat effectiveness declined rapidly in 1944-45 due to losses in personnel and equipment, while the performance of the American infantry divisions continually improved. In World War II, the American people and their political leaders "demanded quick, decisive action to bring the war to a rapid conclusion," and after some initial errors the American infantry divisions were a vital component of this decisive victory over Germany (Mansoor 1999).

German officers writing after the war blamed the Allied superiority in numbers and equipment for their defeat, although American commanders knew that on the Western front at least, the opposing armies were nearly evenly matched in size in 1944-45. In fact, they were always struggling to find enough replacements to maintain the fighting capacity of their infantry divisions, which were almost always understrength....

Although about 85% of German casualties during the war occurred on the Eastern Front, the U.S. was also fighting a two-front war and used about 40% of its troops and resources to the campaigns in the Pacific. Although the German Wehrmacht was well led well trained, and highly organized and disciplined, it was also deficient in use of tactical air power, cooperation with allies and other services, supplies, logistics and intelligence. Certainly its lack of air cover by 1944 was a major factor in its defeat, while American commanders excelled in the use of tactical air power and artillery support. Overall, human, organizational and technical factors improved on the U.S. side, and the American infantry divisions also had high endurance and ability to recover from losses and temporary reversals.
In combat, American infantry troops were flexible, adaptable and resourceful in a wide variety of situations, and superior to the Germany Army in fire support and joint operations. Although the armored units traditionally get most of the credit for the breakout from Normandy in 1944 and the drive across France, in the European Theater of Operations (ETO), the U.S. Army had two infantry divisions for each armored division, and even with the latter tank and infantry battalions were evenly matched. None of the rapid armor movements in France would have been possible without these lesser-known infantry divisions, and in the end "only one division out of eighty-nine completely failed the test of combat when the time came to prove their worth on the battlefield" (Mansoor 1999).

During the Second World War, as the naval campaign drove from the Central and South Pacific toward the Philippines in 1944, American political and military leaders were gravely concerned about the…