General George C. Marshall became Army Chief of Staff in September 1939. He took command of a neglected army, 17th in the world in terms of size. He quickly took note of world events and communicated his concern immediately to US President Franklin D. Roosevelt.
Roosevelt had a strategic dilemma. He did not want but had to prepare for a war on two fronts, Germany in Europe and the Japanese in the Pacific. He wanted to eradicate Nazism, but didn’t want to fight two wars at once that had essentially different causes and demands. He turned to Marshall to implement what he expected to be a war against Nazi Germany. In the event of war with Japan, the United States Navy would have to hold until the Army defeated Germany.
Marshall immediately recognized that massive reorganization was in order. The US Army had no tank corps; it was eliminated after World War I. The few tanks America had were outdated light tanks that could not compare with German tanks then employed in Blitzkrieg tactics in Poland.
The Louisiana Maneuvers of September 1941 showed the prowess of several American officers and led Marshall to notice Dwight D. Eisenhower. General George S. Patton moved his men 380 miles around his enemies’ rear at night. He would later employ similar tactics against the Germans.
When Marshall took office, the United States had 174,000 regular officers and men and 200,000 in the National Guard; by the time of the attack on Pearl Harbor, 1,686,000 men in thirty-six active divisions were available. Most lacked both training and equipment.
But that was not enough. The two-front war would require 200, perhaps as many as 330 divisions. As the war progressed and landings were made all over the Pacific and in North Africa and Italy, the American High Command began to rethink their strategy. Eighty-nine divisions were active as of August 1943, far less than the combined manpower of Germany and Japan.