Lets say that, the German Empire doesn't attack US ships, and the US does not declare war on Germany, they may still send support but not officially be at a state of war with Germany. Without American aid as in our timeline, the Central powers win in Europe.
Britain and France are forced to pay war reparations to the Central powers, some point later on after the war Austria reforms to something like the United States of Greater Austria plan, as in our timeline in order to stay stable, and the Ottomans are probably falling apart, unless something is done.
Would fascist dictators rise in Britain and France, would Germany help the Russian government, and stop the communist forces, which would bleed out into Europe, eventually Britain and France?