<answer>Russia</answer>, as a member of the Holy Alliance, had operated as the "police of Europe", maintaining the balance of power that had been established in the Treaty of Vienna in 1815. <answer>Russia</answer> had assisted Austria's efforts in suppressing the Hungarian Revolution of 1848, and expected gratitude; it wanted a free hand in settling its problems with the Ottoman Empire — the "sick man of Europe". The United Kingdom could not tolerate <answer>Russia</answer>n dominance of Ottoman affairs, as that would challenge the British domination of the eastern Mediterranean.
Who operated as the "police of Europe"?
Russia