Splendid Isolation is the isolationist foreign policy Britain pursued from 1815 to 1902, when the Anglo-Japanese Alliance was formed.

During this period, Britain's primary goal in foreign policy was, firstly, to maintain the balance of power in Europe. If the balance of power was upset, Britain was ready to intervene.

Britain's second goal was to protect its overseas interest in the colonies and dominions, as free trade is what keep the Empire alive. The route to the colonies, especially India, was vital for Britain.

After the unification of Germany, Bismarck initiated the alliance system to prevent France's revenge. Successful alliances began with the Dreikaiserbund and Dual Alliance, 1879. The Triple Alliance was finally formed in 1882 with signatories including Germany, Austria, and Italy.

The rise of Germany in both industrial and military terms alarmed Britain. The Triple Intervention in China deepened the British suspicion of whether it should continue its isolationist policy. On the other side of the world, the Triple Intervention also deeply humiliated Japan, which also realised that a strong ally in Europe was needed for the world to recognition its status as a power.

Finally, Britain's Splendid Isolation was ended by the 1902 Anglo-Japanese Alliance. Britain began to normalise its relations with European countries that it had disputes with, and the Entente Cordiale and the Anglo-Russian entente were signed in 1904 and 1907 respectively. The Alliance System was finally formed in the same year (Triple Alliance and Triple Entente), and it is considered an important factor in the outbreak of World War I.