Teg,
Various and sundry comments:
The Zimmerman Telegram: Sadly, nearly a century after it was composed and dispatched, certain people still question whether it was actually a British forgery.
And this despite Zimmerman himself proudly and repeatedly admitting he'd written the damn thing, despite the various Wilhelmine government records pertaining to it, and despite the cable company's own transmission records. People often forget the role of the cable company records in the affair.
Wilson wasn't just pissed because of the contents of the Telegram. He was also pissed because the herd of boobs running Germany had seen fit to dispatch an alliance proposal aimed against the US on
US State Department telegraph cable which Wilson had personally made available for Germany's use over the protests of his Cabinet. He'd given them access to the cable so that they could directly discuss ceasefire and/or peace terms with him and they'd used it to propose starting a Mexican-American war.
If Britain somehow forged the Telegram, then Zimmerman, his staff who helped prepare it, the various government officials he showed it to before transmission, and the company officials controlling the US cable he dispatched it over were all British agents.
Scotch the Telegram and I think you've a very good chance of keeping the US out of the war and helping the Central Powers win.
Lloyd George and the Convoys: The claims George made in his autobiography about "forcing" the Admiralty to adopt convoying are nothing but lies. Numerous historians, biographers, and George's own son all say so. Furthermore, the Admiralty's own records and those of the War Cabinet all rebut George's claims. When the U-boat crisis hit in 1917, the RN had neither the escorts, antisubmarine weapons, or organization available to begin convoying on a huge scale. It's very telling that the first warships Britain asked the US to send to Europe were not battleships but destroyers, a type of ship the US was also short of.
As it was, the Admiralty organized convoys as the escorts for them became available. Lloyd George had little, if anything, to do with it at all.
Having the 1917 U-boat crisis hit earlier or harder before the escorts can be found is another way to help the Central Powers win.
America and the War: The US didn't win the war by 1918 or even substantially materially assist in helping winning the war by 1918. What the US did was ensure that the Entente could no longer
lose the war. Access to US credit, food, and raw materials had kept the Entente in the war and access after April 6th 1917 to same as allies instead of customers allowed the Entente to prevail in 1918. All the Entente had to do was hold on until the US could play a role and the Entente proved to itself and it's enemies that it could hold when it stymied Germany's final offensives in the spring of 1918 with very little US help.
More importantly, the entry of the US brought with it the assumption that Wilson's sophomoric Fourteen Points were now the avowed war aims of the Entente. Nothing could have been further from the truth as Versailles would later prove, but various nationalist movements ranging from Slovakia to Vietnam all rejoiced and began planning. Within months of the US' entry, national councils in the Austria-Hungary were acting as
de facto national governments complete with loyal troops and even their own
foreign policy.
The entry of the US was a huge morale boost for the Entente and a spark for the disintegration of the second largest Central Power. Austria-Hungary was doomed the moment that the 14 Points were seen as it's enemies' war aims and Germany was doomed the moment Austria-Hungary began to fall apart.
If you can keep the lid on the various nationalist movements inside the Central Powers, you have a good chance of helping the Central Powers win.
Good luck.
Bill