Protecting India
The British by the mid 19th century understood the importance of protecting their Indian Empire. Their adventures in Afghanistan stemmed from the desire to protect the territories that lay west of the Indus but east of the Khyber pass. This led them to protect the gates to India the Khyber, which had been used by many external aggressors to enter India. From Darius I of Persia and Alexander's generals in Ancient times to Mahmud of Ghazni and Muhammad Ghori in medieval times. So did Babur, Nadir Shah and Ahmad Shah Abdali(Durrani). Even Chinggis Khan had crossed the Khyber. Khyber and other passes in north west of India were indeed the gates to India. As long as the Hindu Shahi rulers ruled Afghanistan there was no great danger. It led to the British to also submit to the fact that to guard Khyber one has to be on both sides of the pass. The other far off entry points for India or Indian Ocean was Egypt. The British thus took care to control Egypt and colonised it too. Those who