Following the outbreak of World War I, he was appointed as a general to fight in the Caucasus, initially in the Persian Campaign. His military achievements include his victory in the Battle of Dilman over Khalil Pasha. He also commanded the forces that took Bitlis in the dead of winter, and took his army down through the mountains of Eastern Anatolia to the plains of Mush. He engaged with the Ottoman 3rd Army at the Battle of Mush and captured the city Mush. Later he moved toward Bitlis. The success in Battle of Bitlis led to the furthermost Russian advance into Anatolia. These military achievements earned him the admiration of military critics both in Europe and America. In this position, he supported the British Mesopotamian Army by disrupting supply lines. He established the outposts which made possible the further advance of the British in the Mesopotamian campaign. Following the army's advance beyond Bitlis, he was in close co-operation with the British General Marshal. General Nazarbekov, for his achievements, was decorated by the French Government.