take the lesson to heart.

In the meantime the Shah of Persia, instigated by Russia, besieged
Herat, but after months of fruitless effort, and in consequence of our
sending troops to the Persian Gulf, the Shah at length withdrew his army.

It was not only the hostile efforts of the Shah on Herat in 1838 which
were a cause of anxiety to the Indian Government; but, as Kaye
writes,[Footnote: Kaye's _War in Afghanistan._] 'far out in the
distance beyond the mountains of the Hindoo Koosh there was the shadow
of a great Northern army, tremendous in its indistinctness, sweeping
across the wilds and deserts of Central Asia towards the frontiers of
Hindostan.' That great Northern army, as we know now, but did not know
then, was the column of Perofski, which had left Orenburg for the
attempted conquest of Khiva, but which subsequently perished from
hardships and pestilence in the snowy wastes of the Barsuk Desert, north
of the Aral.

In view of all the circumstances--of the supposed designs of Russia and
Persia, and of the hostility and incessant intrigues in Afghanistan--the
Government of India were sorely perplexed, and opinions amongst the
authorities widely differed as to the policy to be pursued. Lord
Auckland, however, at length decided on the assemblage of a British
force for service across the Indus. In his manifesto issued in December
1838 he first alluded to the Burnes mission, and the causes of its
failure. He then referred to the claims of Shah Soojah, a former ruler
of Afghanistan (who had been living for some years in exile within our
territories) and said we had determined, in co-operation with the Sikhs,
to restore him to power as Ameer of Cabul.