Britain's primary motivation in supporting the Ottoman Empire against Russia (and its serial attempts to prop-up friendly governments in the buffer state of Afghanistan) was to prevent the border of the Russian Empire advancing to meet that of British India. Potential Russian interference with Britain's East Asian trade was also a concern. Following the Great Mutiny of 1857, it was feared that Indian units might be encouraged to rebel should there be a Russian invasion, and might rebel in any case were British Army units in India reduced. This placed a greater importance on reducing garrisons in quieter parts of the empire, and on replacing them where required with locally raised reserve units.