How do we get the US involved in the European wars of the 20th century, and what would be the effects? Would the German and Russian civil wars still happen? would America be viewed as a military hegemon as oppose to an economical one today?
What about military technology, does America still dump all those money into nuclear projects after the first great war anyway? Would Germany and France still develope the super-dreadnoughts while Britain go the way of carriers and airpower?