principle of British policy that Persia was never to possess Herát. Herát and Kandahár were the two points in Western Afghánistán which commanded the lines always followed, from the time of Alexander to that of Ahmad Sháh, by the invaders of India, and which, therefore, it was necessary should be held by the friends of British India, if not by British India herself. During the first war waged by Great Britain with Afghánistán, Persia had posed as a pawn pushed forwards by Russia to gain a dominant position on the Indian frontier. But, in 1838, Russia was disinclined to support her pawn. She was more prepared for action when the Crimean war broke out. But when the Sháh of Persia realised the fact that the powerful nation which had filched from him some of his most fertile provinces was in deadly grip with England and France, he suspended his insidious action regarding Herát until he should be able to form a definite opinion as to the result of the struggle. He resumed that insidious action as soon as he recognised that the peace of Paris had given Russia a free hand to subdue the barrier of the Caucasus. Regarding Russia as fully occupied, and England as exhausted, he despatched an army to besiege Herát. The ruler of the province of which Herát was the capital, who occupied a position of semi-independence, at once hoisted British colours, and implored the assistance of the Amír Dost Muhammad. Various circumstances, into which it is not necessary to enter, gave indications that the Persians would be resisted to the last. However, it was not so, and before any steps could be taken Herát had fallen.
The clear mind of the then Prime Minister of Great Britain, the resolute Lord Palmerston, had already recognised the importance of the situation, and he resolved to compel Persia to retire. The means he adopted were those
