In Britain, too, many citizens felt the government was neglecting the defence of that island by deploying much of the army around the World on garrison duty. The Militia and the Yeomanry (which could no longer rely on compulsory service), together with the regular army units that did remain in Britain, were unable to field forces thought adequate for the defence of the island against a large, modern continental army. Following the Crimean War, when reserve forces had to be dispatched to the war zone, it was realised that the British Army's Imperial garrison obligations not only left Britain vulnerable, but also did not leave aside sufficient uncommitted forces to compose an effective expeditionary force such as had been required in the Crimea. Britain's primary motivation in supporting the Ottoman Empire against Russia 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 Indian Mutiny of 1857, it was feared that Indian units might be encouraged to mutiny should there be a Russian invasion, and might mutiny in any case were British units in India reduced in number.