Earlier victory by Entente, say some time in late 1915. Leading to easier peace terms with Germany and perhaps even some sort of Danube confederation surviving. Some sort of collapse in Russia and France helping Germany to defeat communists in Berlin, or something like that.
In any case, regardless of when war ends, better peace terms after the war, allowing for less resentment and faster reconciliation between France and Germany.
By, say 1917, Germany and France reestablish trade and to prevent the repeat of the war start integrating markets.
Crucial ideas would be to:
- prevent spread of communism
- prevent repeat of the war
- secure the continuing domination of Europe in world affairs.
Preventing this outcome is the fact if the war is not bloody enough and ends early, it probably butterflies away communism and fear of repeating the war.