London Naval Conference (December 1935 - March 1936)

Tensions in the Pacific preceding World War II caused a second round of conferences to be held in London in 1935-36. The provisions in the 1922 Washington treaty that prohibited the powers from building new capital ships were set to expire in 1936, as were the provisions of both the Five-Power Treaty of 1922 and the 1930 treaty. In 1935, the powers met for a second London Naval Conference to renegotiate the Washington and London treaties before their expiration the following year.

Great Britain, France, and the United States signed an agreement declaring a six-year holiday on building large light cruisers in the 8,000 to 10,000 ton range. On 25 March 1936 a naval agreement between France, United States, Britain, Australia, Canada, India, and New Zealand was signed. "Desiring to reduce the burdens and prevent the dangers inherent in competition in naval armament; and Desiring, in view of the forthcoming expiration of the Treaty for the Limitation of Naval Armament signed at Washington on the 6th of February, 1922, and of the Treaty for the Limitation and Reduction of Naval Armament signed in London on the 22nd of April, 1930, ... to make provision for the limitation of naval armament, and for the exchange of information concerning naval construction; ..." That final decision marked the end to the decade-long controversy over cruisers. And on 06 November 1936 Australia, Canada, France, Britain, India, Ireland, Italy, Japan, New Zealand, South Africa, and the United States signed a procés-verbal continuing the 1930 treaty on submarine warfare.

Adolf Hitler came to power in Germany during 1933, denounced the Treaty of Versailles, and embarked on rearmament. Germany renounced the disarmament clauses of the Treaty of Versailles on 16 March 1935. Britain attempted appeasement with Germany in 1935 and 1936, including the Anglo-German Naval agreement in 1935 permitting Germany to rebuild its Navy. The British at first accepted what seemed limited rearmament proposals in the hope that the Germans would peg their demands. On 18 June 1935 Chancellor Hitler signed a naval treaty with Britain limiting the German fleet to 35 per cent of that of the Royal Navy, while their submarine service could be up to 45 per cent or up to parity should it be deemed desirable by the Germans and the British agreed. Even most of the Admiralty staff supported the 1935 Anglo-German Naval Agreement, which at last recognised Germany's right to rebuild a submarine fleet. Upon this signing, the British Government stated that "His Majesty's Government in the United Kingdom regard this proposal as a contribution of the greatest importance to the cause of future naval limitation. They further believe that the agreement which they have now reached with the German Government, and which they regard as a permanent and definite agreement as from today between the two Governments, will facilitate the conclusion of a general agreement on the subject of naval limitation between all the naval Powers of the world." On 29 February 1936, the German Government informed the British of their willingness to enter negotiations for a bilateral naval agreement. Britain had invited such negotiations with a view to incorporating the terms of the general treaty to be signed at the London Conference in order to prevent Germany from initiating a competition in types contrary to qualitative limitation.

On 27 February 1936 Italy intimated her inability to sign any naval agreement. Unwilling because the Powers were imposing sanctions on her, Italy said she was not satisfied with the proposed size of battleships and zone of no construction.

In 1935, Britain and France had acquiesced to Germany's abrogation of its disarmament obligations. In March 1936, Hitler ordered the remilitarization of the Rhineland, betting correctly that the world's would not respond.

The entire naval arms control effort failed when Japan effectively abrogated the earlier pacts. On 15 January 1936 Japan withdrew from the London Naval Conference, stating "... as it has become sufficiently clear at today's session of the First Committee that the basic principles embodied in our proposal for a comprehensive limitation and reduction of naval armaments cannot secure general support. ... we regret to state that we cannot subscribe, for the reasons we have repeatedly set forth, to the plans of quantitive limitation submitted by the other Delegations." On 23 June 1936 Japanese Cabinet decided formally not to adhere to the London Naval Treaty. (Japan's prestige and her material interests would best be served by the retention of complete freedom in regard to the types as well as to the numbers of her warships. Freedom from the obligation to make her naval plans known was considered to outweigh the advantage of receiving information in advance regarding the building programs of other signatories. The Japanese Navy's shipbuilding policy after December 1936 ignored qualitative restrictions in all classes of warship.

The expiration of the naval limitations agreements re-opened the possibility that the United States might fortify Guam, thus partially neutralizing the Japanese position in its mandates (which were presumably being fortified, since it had become impossible to gain access to them or much intelligence about them). The Congress refused to authorize this step. In the summer of 1937 the Japanese began an undeclared war in China, bringing closer the moment at which the United States must choose either to accept or contest Japanese aims.

Germany launched two battleships of the Scharnhorst class in 1936, to followed two years later by a pair of even mightier ships of the Bismarck class. France first responded, building two fast battleships of the Dunkerque class. Italy reacted by the construction of its first thirty-five-thousand-ton battleship, the Vittorio Veneto. In 1935 France announced contracts for a Richelieu class, two battleships of 38,500 tons each. Italy responded with two more heavy battleships, while England started five King George V-class battleships, thirty-eight thousand tons each. The United States produced two North Carolinas and four South Dakotas, armed with nine sixteen-inch guns and exceeding thirty-five thousand tons. Last, the Japanese started to build in 1937 the four Yamato-class battleships.