Second London Naval Treaty

Second London Naval Treaty. The Second London Naval Treaty was a significant but ultimately faltering international arms control agreement negotiated in the mid-1930s. It aimed to extend and modify the quantitative and qualitative limitations on naval construction established by the Washington Naval Treaty of 1922 and the First London Naval Treaty of 1930. Faced with the withdrawal of Japan and the non-participation of Italy, the final pact was signed only by Great Britain, the United States, and France, and its restrictive clauses were largely rendered ineffective by the outbreak of the Second World War.

Background and negotiation

The diplomatic landscape for naval arms control had deteriorated significantly by the early 1930s. The rise of militaristic governments in Japan and Germany, the latter having repudiated the Treaty of Versailles, created profound insecurity. The First London Naval Treaty was due to expire in 1936, prompting the major naval powers to convene the Second London Naval Conference in late 1935. The negotiations were immediately jeopardized when the Empire of Japan, demanding parity with the United States Navy and the Royal Navy, formally withdrew from the conference in January 1936. The Kingdom of Italy also refused to sign, largely in protest over League of Nations sanctions related to its invasion of Abyssinia. This left only the United Kingdom, the United States, and France as primary negotiators, with the Soviet Union attending as an observer.

Key provisions and limitations

The treaty established two tiers of obligations: one for the three signatories and an "escalator clause" that could be invoked if a non-signatory engaged in excessive building. Core qualitative limits included a reduction in the maximum standard displacement of battleships to 35,000 tons and a cap on main gun caliber at 14 inches. Cruiser tonnage was capped at 8,000 tons with guns no larger than 6.1 inches, and destroyer limits were set at 1,850 tons with 5.1-inch guns. A critical innovation was the qualitative limit on submarines, restricting them to 2,000 tons and 5.1-inch guns. The treaty also included advance notification and exchange of information on building programs. However, the escalator clause allowed signatories to increase battleship gun caliber to 16 inches if a non-signatory did so, a provision soon triggered by Japan.

Signatories and ratification

The treaty was formally signed in London on 25 March 1936 by representatives of the United Kingdom, the United States, and France. Ratification processes proceeded, with the treaty entering into force on 29 July 1937. Several other nations, including members of the British Commonwealth like Australia and Canada, acceded to the treaty later. Notably, neither the Imperial Japanese Navy nor the Regia Marina of Italy became parties, fundamentally undermining the treaty's global authority. The Kriegsmarine of Nazi Germany was not a participant, being bound only by the separate Anglo-German Naval Agreement.

Impact and consequences

The practical impact of the treaty was limited from its inception. In 1938, invoking the escalator clause due to Japanese construction, the United States, Britain, and France agreed to raise the battleship gun limit to 16 inches. This directly influenced the design of new capital ships like the American ''North Carolina''-class and the British ''King George V''-class. The treaty failed to halt a qualitative naval arms race, particularly in cruiser and destroyer design where nations pushed against tonnage limits. It also did nothing to constrain the massive building programs of Japan or the clandestine development of the German ''Bismarck''-class. The Munich Agreement and subsequent German occupation of Czechoslovakia further eroded any political will for arms limitation.

Termination and legacy

The treaty was effectively terminated by the onset of the Second World War. While its formal expiration date was set for 31 December 1942, its provisions were universally ignored after the war began in September 1939. Its legacy is one of a well-intentioned but ultimately futile effort to maintain the interwar period's system of naval arms control in the face of rising Axis aggression. The failure of the treaty signaled the definitive end of the restrictive system begun at the Washington Naval Conference and highlighted the inability of diplomatic agreements to contain the expansionist ambitions of Imperial Japan and Fascist Italy. Post-war naval limitation would take a different form, eventually evolving into the strategic arms control talks of the Cold War era.

Category:Naval treaties Category:1936 treaties Category:Arms control treaties Category:Treaties of the United Kingdom Category:Treaties of the United States Category:Treaties of France Category:Military history of World War II