The Alliance system was originally based on Bismarcks attempt to isolate France and avoid a two-front war. Wilhelm II's over-confidence in the Schleiffen Plan as a means to win a two-front war, and his underestimating of his personal influence over his cousin Nicholas II, leads him to end the non aggression pact with Russia and rely on the public Triple Alliance to keep Russia out of any war Germany may have to fight against France, as well as with his relatives in Britain whom he wrongly assumed would not fight on the continent.
But by 1920, Italy, which waned at the outbreak of War in 1914 and eventually joined the Allies in 1915, might no longer be allied to Germany and Austria-Hungary. They may even be allied with France over her shared rival interests against Austria-Hungary in Southern Europe. An Emperor Franz Ferdinand will be dealing with internal ethnic issues, and though he most likely will stay allied with Germany because of a possible threat on its eastern border against Russia, and former ally Italy now possibly on opposing sides, he would likely not want to risk any aggressive moves in the Balkans that may threaten a war to both his eastern and southern borders.
Germany may need to rethink its strategy without Italy, whom they will have lost as a prospective ally at France's southern border, and consider toning down their naval and colonial rivalry with Britain in an attempt to keep her from joining with Russia in any alliance against them. This could be feasible because Russia by 1920 may pose a threat to the British in areas such as Afghanistan, the Middle East, and of course how the British might deem Russia to be a threat to their Empire's crown jewel colony of India.
Maybe if things hold off till 1920, common sense, which was completely absent it seems in 1914, will prevail in 1920.