What would have happened had USA joined World War 2 sooner?

Answer 1

The main thing to happen is that total US combat casualties would have been much higher because the US was not ready earlier. Combat wise, the US could have made very little contribution to the war. Following WW1, and during the Depression, the US Military [Army, Navy, Marine Corps, and the Army Air Corps] were severely cut back to the point of being usless in a major war. The US used the time before it actually entered combat to do several things. 1. It geared up its war material manufacturing system to produce weapons, munitions, vehicles of all types, combat rations, medical capabalities, and probably dozens of other crucial items [that I can't recall at the moment] needed for successful prosecution of a major war. 2. During this time, although not in a combat role, it provided the above items, in massive quantities, to those allied countries already involved. 3. Also during this time, the draft gathered the manpower needed for the war to come, and the Army, Navy, Marine Corps, Army Air Corps, Coast Guard, Merchant Marines, and civilian home guard units built up their manpower strength, and trained and prepared for our entry. By doing it this way, the US made a greater contribution to the aid of the allied military forces than if it had immediately jumped into combat.

Answer 2

Because it didint want to be involved in the war against Nazi Germany or Japan. It had witnessed the Horror of World War I and did not want to get involved in another European war. At this point, the country was also involved in the Great Depression, so it was more concerned with domestic affairs than getting itself involved abroad. Gradually, our alliances with Great Britain won out and we began instituting programs like Lend Lease to aid them. It wasn't until the Japanese attacked Pearl Harbor on December 7, 1941 that the United States finally overcame its isolationism.