In 1919, Afghanistan invaded British India and precipitated the short Third Anglo-Afghan War. Although this Anglo-Afghan War was more limited than the first two, it drove defeated Afghanistan toward Revolutionary Russia. The Kingdom of Afghanistan worried about Britain's intentions and so Afghanistan became the first country to recognize the new Bolshevik government. Relations improved to the point that In May 1921, the Kingdom of Afghanistan signed a treaty of friendship with the Soviet Union. The British perceived the recognition and the treaty as a threat to British India. There were fears...