London Naval Conference, 1930

Documents of the London Naval Conference, 1930

By 1929, interwar naval arms control had ground to a halt. After the initial success in disarming the defeated powers from World War One, followed up by the successful Washington Naval Conference which achieved major reductions in battle fleet force levels, there had been a series of failed initiatives. The Rome Conference had failed to extend the Washington Treaty limits to other nations, the Geneva Naval Conference had failed to extend the Washington Treaty limits to auxiliary warships, and the Preparatory Conference had dragged on interminably, without any tangible progress.

After the failure at Geneva, there were three principal problems to be resolved in order to progress naval limitation. First, the problem of Anglo-American parity in cruisers had to be resolved – Britain required far more cruisers than the US was willing to build, and the US wanted to build larger cruisers armed with 8-inch guns, while Britain favoured smaller cruisers armed with 6-inch guns. Second, an agreement was required between the Anglo-Saxon powers and Japan on the ratio to be applied to auxiliary warships – Britain and America wanted to extend the 60 percent ratio agreed at Washington, whereas Japan was determined to achieve 70 percent. Finally, agreement was required between France and Italy on an appropriate ratio between the two Mediterranean powers that satisfied both of their aspirations, without compromising Britain’s position vis-à-vis the US and Japan.

The election of Herbert Hoover as US President in 1929 created an opportunity for a new direction in naval arms control. Prior to his inauguration he wrote to his predecessor asking him not to act on the fifteen-cruiser bill, as he did not want any funds appropriated or planning begun which might jeopardise a settlement with Britain. In his inaugural address on 4 March 1929 Hoover stated that the Kellogg-Briand Pact – an anti-war treaty signed in 1928 “should pave the way to greater limitation of armament, the offer of which we sincerely extend to the world.” With a new Government in London headed by Ramsay MacDonald echoing similar sentiments, negotiations between the two English-speaking powers progressed through 1929 to the point where it was believed a multi-national conference had reasonable prospects of success. In July 1929, Japan indicated that it was ready to participate in a conference, provided it sought reduction in armaments rather than just limitation, and within a week Britain suspended the orders for two new cruisers (Northumberland and Surrey), and the US had stated that three projected cruisers would not be laid down for the time being.

The 1930 London Naval Conference (LNC30) met from 21 January – 22 April 1930 and resulted in the conclusion of the 1930 London Naval Treaty (LNT30). It was a major event – for example the delegation which US Secretary of State Stimson led to LNC30 was the largest official mission to leave the US since the Paris Peace Conference of 1919. From a political standpoint LNC30 appeared to be a success. The Anglo-American cruiser issue was resolved, and an innovative solution was found to paper over ratio differences with Japan, although no solution was found to Franco-Italian differences. But with the benefit of hindsight, LNT30 turned out a disaster – British naval power was neutered to a degree which compromised her great power status, and nearly resulted in defeat during the initial years of World War Two; the Treaty was roundly rejected in the USN – every single member of the USN General Board testifying against the Treaty during Senate hearings; while in Japan, the Treaty triggered a series of events, including political assassinations that ultimately contributed to the outbreak of the Pacific War.