The London Naval Treaty was an agreement between Great Britain, Japan, France, Italy and the United States, signed on 22 April 1930. Seeking to address a loophole in the formidable 1922 Washington Naval Treaty, it regulated submarine warfare and limited naval shipbuilding. Ratifications were exchanged in London on 27 October 1930, and the treaty went into effect on the same day. It was largely ineffective.
Conference
The signing of the treaty remains inextricably intertwined with the ongoing negotiations which began before the official start of the London Naval Conference of 1930, evolved throughout the progress of the official conference schedule, and continued for years thereafter. During the first four decades of the twentieth century, Prince Iyesato Tokugawa led a political movement in Japan that promoted democracy and international goodwill with the U.S., Europe, and Asia. During the 1921-1922 Washington Naval Conference Tokugawa headed the Japanese delegation that ratified that treaty. The Dec. 23rd, 1929 photo to the right presents the Japanese again participating in the renewal of the 22 Washington Naval Treaty.
Terms
The terms of the treaty were seen as an extension of the conditions agreed in the Washington Naval Treaty, an effort to prevent a naval arms race after World War I. The Conference was a revival of the efforts which had gone into the Geneva Naval Conference of 1927. At Geneva, the various negotiators had been unable to reach agreement because of bad feeling between the British Government and that of the United States. The problem may have initially arisen from discussions held between President Herbert Hoover and Prime Minister Ramsay MacDonald at Rapidan Camp in 1929, but a range of factors affected tensions, exacerbated by the other nations at the conference. Under the treaty, the standard displacement of submarines was restricted to 2,000 tons, with each major power being allowed to keep three submarines of up to 2,800 tons and France one. Submarine gun caliber was also restricted for the first time to with one exception, an already-constructed French submarine allowed to retain guns. That put an end to the 'big-gun' submarine concept pioneered by the British M class and the French Surcouf. The treaty also established a distinction between cruisers armed with guns no greater than from those with guns up to . The number of heavy cruisers was limited: Britain was permitted 15 with a total tonnage of 147,000, the U.S. 18 totalling 180,000, and the Japanese 12 totalling 108,000 tons. For light cruisers, no numbers were specified but tonnage limits were 143,500 tons for the U.S., 192,200 tons for the British, and 100,450 tons for the Japanese. Destroyer tonnage was also limited, with destroyers being defined as ships of less than 1,850 tons and guns not exceeding. The Americans and British were permitted up to 150,000 tons and Japan 105,500 tons. Article 22 relating to submarine warfare declared international law applied to them as to surface vessels. Also, merchant vessels that demonstrated "persistent refusal to stop" or "active resistance" could be sunk without the ship's crew and passengers being first delivered to a "place of safety." Article 8 outlined smaller surface combatants. Ships less than 2,000 tons, with guns not exceeding, with a maximum of four gun mounts above, without torpedo armament and not exceeding were except from tonnage limitations. The maximum allowed specifications were designed around the Bougainville-class avisos then entering French service. Warships under 600 tons where also completely exempt. This led to creative attempts to utilize the unlimited nature of the exemption with the Italian Spica-class torpedo boats, Japanese Chidori-class torpedo boats, French La Melpomène-class torpedo boats and British Kingfisher-class sloops. The next phase of attempted naval arms control was the Second Geneva Naval Conference in 1932; and in that year, Italy "retired" two battleships, twelve cruisers, 25 destroyers, and 12 submarines—in all, 130,000 tons of naval vessels. Active negotiations amongst the other treaty signatories continued during the following years. That was followed by the Second London Naval Treaty of 1936.
