London Naval Conference

Anthony John and Shusuke Maeda

Great Britain, in May of 1930, hosted the London Naval Conference in London. This conference was the third of the five meetings. The meeting was held in order to promote disarmament after World War I. The London Naval Conference was the conclusion of the Washington conference which was held in 1921-1922. There was a unsuccessful meeting in Geneva in 1927, so Great Britain, US, Japan, France, and Italy got together in London in 1930 to make an attempt to revise the Five Power Treaty of 1922. At the conference (lasting 3 months, January 21 - April 22) they discussed the results of the Washington Naval Treaty of 1922 with the representatives of U.S., France, Japan and Italy. There were two groups in the conference: Britain, France, and Italy versus the U.S., Japan and Britain. This division created many nation disputes and affected the flow of the conference.

The Washington Naval Conference establish a ratio of 5:5:3 for capital ships (every five capital ships the American and British had, the Japanese were allowed to have three). Japan, in 1927, suggested on increasing the ratio from 5:5:3 to 10:10:7. The official treaty granted the 10:7 ratio on the light cruisers and destroyers and maintained the 10:6 ratio on heavy cruisers, but with the agreements that US delayed its shipbuilding program to give Japan a grace period with a 10:7 ratio in heavy cruisers.

The main topic at the conference was the battleship tonnage of the U.S., Britain, and Japan. The US was stubbornly opposed to any maximum lower than 10,000 tons because light cruisers were not much use. Although the agreements was reached with the Japanese on the ratio and the heavy cruisers, the US refused to compromise. Even though Britain and other countries agreed, US position prevailed. The last treaty limited tonnage of auxiliary ships and the size and gun power of submarines and destroyers. Japanese was granted the 10:10:7 ratio they were looking for for all non offensive ships. The max tonnage for cruisers was set at 339,000 tons for Great Britain, 323,500 tons for the U.S., and 208,850 tons for Japan. The max number of these cruisers was set at 18 for the U.S., 15 for Great Britain and 12 for Japan. 

Although the meeting was described as an "arms limitation conference," it set limits above the current capacity of some powers involved. In 1935, the powers met for a SECOND London Naval Conference to renegotiate the Washington and London treaties. The Japanese walked out of the conference but the other powers agreed and signed the 6 year break on building large cruisers in the 8,000 to 10,000 ton range. This decision marked the end of the long controversy over cruisers.