Until the beginning of the nineteenth century, the Assyrians belonging to either of the two branches of Eastern Christianity (Jacobite and Nestorian) remained little known community scattered throughout Ottoman and Persian territory. They were supposed to be the earliest Christians and spoke the same language as the Jesus had spoken. When they were discovered by the Western scholars, missionaries and archeologists in the mid-nineteenth century, they were called as "the lost tribe" with great excitement. This theory invested the people with a fictitious, sentimental interest. It is based on a supposed tradition among the people themselves and upon certain resemblances in customs to the Jews. But after that time the internal unity and the external relations of Assyrian community underwent a drastic change. Western Christianity, particularly protestant missionaries exerted their power and influences by using schools and hospitals as the instruments and split the Assyrians along sectarian lines. In terms of external relations this process simply alienated Assyrians from Ottoman and Persian authorities and increased animosity with the Turks and the Kurds who were their neighbors for so long in the same territories. When World War I started, they found themselves inevitably in the midst of the conflict between the Ottoman Empire and the Allied powers. While Jacobites kept generally their silence during the war being faithful to the Ottoman administration; Nestorians became a part of the war by encouragement of Russia and Britain and took their place in World War I as "the smallest ally" of the Allies. The purpose of this paper is to analyze the position of the Assyrians in the Allied political maneuvers during the WW I. As the "smallest ally" of the Allies how they had turned to the losers and although they had spent sufficient effort during the war, why they had not taken their share in the new order formed in Middle East after the war are the questions to be dealt with.