@Flashman:
But in reality the AEF only made an impact in Europe in the Summer of 1918. It took them a long time to organize an army, ship it to France, equip it with British and French weaponry, and train it in modern warfare.
In addition, General Pershing insisted that they only fight in American army divisions; he wasn’t having them just reinforce the Allied positions under foreign command.
Its also totally unfair that America can build an army without the slightest chance for the CPs to attack it. Right up 'till early 1917, America was firmly isolationist and had no intention of spending money on a modern army.
http://en.wikipedia.org/wiki/American_Expeditionary_Forces
Let’s not forget, however, that America had just fought a multi-theatre war against Spain not 20 years before, and intervened in the Mexican Revolution earlier that year. The idea that they were a completely backwards, non-modern power is a bit of an overstatement.
True, by 1917 they hadn’t had the experience of 3 years of brutal modern combat that the Brits and the French had, and they certainly didn’t want to switch their heavy industry over to tank and weaponry production, but by the early 20th century, America was definitely a world player.