Perhaps the most important issue for British foreign policy during the 19th Century was the "Great Game", or the Anglo-Russian rivalry in Central Asia. Russia saw Central Asia (and the Caucuses and Siberia) as frontiers for conquest and settlement, while Britain was extremely concerned about the security of India, and lived in fear of a Russian invasion that would end their rule over the subcontinent.

The Great Game was a central issue in British foreign policy, and was a major factor in many of the most consequential decisions of the century - Britain's support for the Ottoman Empire and entry into the Crimean War, the construction of the Suez Canal and occupation of Egypt, the lack of British intervention in the American Civil War, the Anglo-Japanese Alliance, the various British invasions of Afghanistan, and more.

But how much of a threat to Britain, specifically British India, did Russia actually pose? The threat loomed extremely large in the minds of British leadership, but overestimation of the enemy is not unknown.

• Central Asia at this time was undeveloped and likely unable to support the large armies, and Russia as a whole struggled with the logistics needed to supply its armies in every conflict it fought, from the Crimean War to World War 1.

• While the Anglo-Sikh Wars and Indian Rebellion show that British rule in India had vulnerabilities, a different imperial state doesn't seem to be particularly able to exploit those weaknesses.

• British forces in India were numerous, though of inferior training and equipment than the regular army

• Russia lacked much of an oceangoing navy, and certainly could not seriously challenge Britain at sea

Were British policymakers just paranoid, or did the Russian Empire really pose a serious of a threat to British rule in India and elsewhere ?