Amanullah’s ten years of reign initiated a period of dramatic change in Afghanistan in both foreign and domestic politics. Amanullah declared full independence and sparked the Third Anglo-Afghan War. Amanullah altered foreign policy in his new relations with external powers and transformed domestic politics with his social, political, and economic reforms. Although his reign ended abruptly, he achieved some notable successes, and his efforts failed as much due to the centripetal forces of tribal Afghanistan and the machinations of Russia and Britain as to any political folly on his part.

Amanullah came to power just as the entente between Russia and Britain broke down following the Russian Revolution of 1917. Once again Afghanistan provided a stage on which the great powers played out their schemes against one another. Amanullah attacked the British in May 1919 in two thrusts, taking them by surprise. Afghan forces achieved success in the early days of the war as Pashtun tribesmen on both sides of the border joined forces with them.

The military skirmishes soon ended in a stalemate as the British recovered from their initial surprise. Britain virtually dictated the terms of the 1919 Rawalpindi Agreement, a temporary armistice that provided, somewhat ambiguously, for Afghan self-determination in foreign affairs. Before final negotiations were concluded in 1921, however, Afghanistan had already begun to establish its own foreign policy, including diplomatic relations with the new government in the Soviet Union in 1919. During the 1920s, Afghanistan established diplomatic relations with most major countries.