Third Afghan War, the British-Afghan War of 1919 began on May 06th 1919, when the Emirate of Afghanistan invaded British India and ended with an armistice on 8 August 1919. The war resulted in a treaty with the Afghans gaining control of foreign affairs from Britain, and the British recognizing the Durand line as the border between Afghanistan and British India., it was a strategic victory for the British because the Durand Line was reaffirmed as the border between Afghanistan and the British Raj, and the Afghans agreed not to foment trouble on the British side.