of the buffer kingdom of Afghanistan. The Ottoman Empire in Europe in the sixteenth and seventeenth centuries, when its fortunes began to decline from their zenith adopted an analogous policy of client-states in the Christian territories of Transylvania, Moldavia, Wallachia, and Ragusa.
It has been by a policy of Protectorates that the Indian Empire has for more than a century pursued, and is still pursuing, its as yet unexhausted advance. First it surrounded its acquisitions with a belt of Native States with whom alliances were concluded and treaties made. The enemy to be feared a century ago was the Maratha host, and against this danger the Rajput States and Oude were maintained as a buffer. On the North-west Frontier, Sind and the Punjab, then under independent rulers, warded off contact or collision with Beluchistan and Afghanistan, while the Sutlej States warded off contact with the Punjab. Gradually, one after another, these barriers disappeared as the forward movement began: some were annexed, others were engulfed in the advancing tide, remaining embedded like stumps of trees in an avalanche, or left with their heads above water like islands in a flood. When the annexation of the Punjab had brought the British power to the Indus, and of Sind, to the confines of Beluchistan; when the sale of Kashmir to a protected chief carried the strategical Frontier into the heart of the Himalayas; when the successive absorption of different portions of Burma opened the way to Mandalay, a new Frontier problem faced the Indian Government, and a new ring of Protectorates was formed. The culminating point of this policy on the western side was the signature of the Durand Agreement at