It maybe appropriate to go back through OTL and examine all major USA interactions/interventions and alter the outcomes.
For instance the Zimmerman Telegram debacle ...
Perhaps strengthen US German diplomacy say through more supply sub visits of the Deutschland, U151 type.
"American submarine pioneer Simon Lake visited the Deutschland while she was in Baltimore, and made an agreement with representatives of the North German Lloyd line to build cargo submarines in the US."
https://en.wikipedia.org/wiki/German_su ... eutschland
Perhaps stage a Zeppelin transAtlantic flight instead of bombing London! The Africa flight of LZ 104 was 6800km in 11/17.
Lots of scope for building German/US entente.
All of 1916 history onwards will be different. Less ammunition supply for France during battle of Verdun etc.
The French mutiny of 1917 would have far worse consequences without Petain having US supplies to consider.
https://en.wikipedia.org/wiki/French_Army_Mutinies
and the British mutinies of 1917 may well have also cascaded into a general collapse
http://leftfootforward.org/2014/08/ww1- ... and-riots/
Aussies were involved here because we don't tolerate uppity Poms tellin' us what to do!!!!
"On 28 August 1916, a member of the Australian Imperial Force (AIF), Private Alexander Little (10th Battalion; no. 3254), verbally abused a British NCO after water was cut off while he was having a shower.[6] [7] As he was being taken to the punishment compound, Little resisted and was assisted and released by other members of the AIF and the New Zealand Expeditionary Force (NZEF). Four of these men were later identified, court-martialled, convicted of mutiny and sentenced to death, including Little. Three had their sentence commuted. While the military regulations of the AIF prevented the imposition of capital punishment on its personnel, that was not the case for the NZEF. Private Jack Braithwaite, an Australian serving with the NZEF, in the 2nd Battalion of the Otago Regiment, was considered to be a repeat offender — his sentence was confirmed by General Douglas Haig and he was shot by a firing squad on 29 October."
So you could construct an AU around such events.
A 1918 German offensive would have been far more successful, Aussie resistance noted but wasted by British officers, if they were still holding together after the mutinies. An interesting but usually overlooked aspect of the German advance was the looting of cellars and cheese stores and this brought many units to a standstill - Ch 20 'A Victory Party Turns into a Hangover'.
Kiester, Edwin (2007). An Incomplete History of World War I. Murdoch Books. ISBN 1-74045-970-9
Without US supplies such armies as the Australian Corp with our brilliant General Monash would never have come into existence. It was the largest all arms army corps of the entire British armed forces with better aircraft and armour coordination than any one else.
So you've lots of POD to explore adn it should make for an excellent AU, congratulations on undertaking such an adventure!