Foreign interference in Persia did not begin with the war. The Anglo-Russian Treaty of 1907 had already carved the country into spheres of influence: Russia claimed the north, adjacent to its conquered territories in the Transcaucasus, while Britain took the south, bordering British India. A buffer zone separated them. Oil deepened the stakes. On 26 May 1908, the first commercially significant oil strike in the Middle East had been made in Persia, and by 1914 the British government had contracted with the Anglo-Persian Oil Company to fuel the Royal Navy. Germany added a third layer of maneuvering, establishing its Intelligence Bureau for the East to foment nationalist agitation in Persia and undermine the Anglo-Russian alliance. The bureau's operations in Persia were led by the adventurer Wilhelm Wassmuss, sometimes called the 'German Lawrence.'

Each invading power wanted something different. Ottoman War Minister Enver Pasha dreamed of pan-Turanian unity -- if Ottoman forces could defeat the Russians in Persia's key cities, the road would open to Azerbaijan, Central Asia, and ultimately India. Russia wanted to protect its Armenian and Assyrian Christian populations in northern Persia and maintain control of the approaches to the Caspian Sea's hydrocarbon resources. Britain needed to secure Mesopotamia's oil and keep the rival powers from threatening India. The Persian government, meanwhile, could barely keep order within its own borders. Before the war, Qashqai tribesmen in the south raided at will, Khamseh raiders terrorized caravan routes in Kerman, and the central gendarmerie held only the main roads. Into this fragmented landscape, three empires marched their armies.

The heaviest fighting consumed the provinces of Iranian Azerbaijan -- East Azerbaijan, West Azerbaijan, and Ardabil. Russia had already occupied Tabriz in 1909 and Urmia and Khoi by 1910, stationing the Persian Cossack Brigade and Armenian volunteer units under General Andranik Ozanian. When Ottoman forces entered in late 1914, the region became a shifting mosaic of advances and retreats. Armenian volunteers repulsed Ottoman commander Khalil Bey's attacks, then pushed east to capture Bashkaleh in May 1915. By 1916, the Ottoman XIII Corps under Ali Ihsan Bey had seized Kermanshah and Hamadan, forcing Russian General Baratov to retreat north after losing half his men. Cities changed hands repeatedly. In June 1918, the Ottoman IV Corps entered Tabriz itself. The civilian populations -- Armenians, Assyrians, Kurds, Persians -- were caught between the armies, subject to massacres, forced displacement, and starvation.

The war's most devastating weapon in Persia was hunger. The Persian famine of 1917-1919, worsened by the disruption of agriculture and supply routes under occupation, killed the majority of the two million civilians who perished. Ethnic minorities suffered particularly. By 1918, roughly half of the Assyrian population of Persia had died from massacres, starvation, and disease. An estimated 80 percent of Assyrian clergy and spiritual leaders perished, threatening the survival of the community as a coherent people. Armenian civilians faced the genocidal violence already consuming their kin in Ottoman Turkey. Archbishop Nerses Melik-Tangian of Tabriz wrote to the Crown Prince of Azerbaijan pleading for protection, a letter that survives as testimony to the desperation of communities trapped between warring empires that recognized no obligation to the people on whose land they fought.

The war's aftermath transformed Persia's political order. The Anglo-Persian Agreement of 1919 granted Britain drilling rights and attempted to establish a protectorate over the country. British General William Edmund Ironside occupied northern Persia to enforce the armistice terms. But the arrangement proved unstable. Soviet forces threatened from the north, and the pro-Turkish parliament was forced to disband. In 1921, a military coup brought Reza Khan, an officer of the Persian Cossack Brigade, to power. By 1925 he had established the Pahlavi dynasty, curtailing the parliament and centralizing authority. The Qajar government's inability to defend Persian sovereignty during the war had discredited the old order. From the ashes of a conflict Persia never chose to enter, a new Iran was forged -- one that would carry the scars of foreign occupation into the modern era.