The signatories were the governments of France, Great Britain, and the United States of America. The government of Japan, which had been a signatory of the First London Naval Treaty, had withdrawn from the conference on January 15. Italy also declined to sign the treaty, largely as a result of public hostility over her invasion of Abyssinia.
The conference was intended to limit the growth in naval armaments until its expiry in 1942. The absence of Japan (a very significant naval power) prevented agreement on a ceiling on the numbers of warships. The treaty did limit the maximum size of the signatories' ships, and the maximum calibre of the guns which they could carry. For example, submarines could not be larger than 2000 tons or have a gun armament of greater than 5.1-inches, cruisers were restricted to 8000 tons or less and capital ships to 35000 tons and 14-inch guns.
See also: Washington Naval Treaty, Anglo-German Naval Pact