Ten interesting facts about the Washington Naval Treaty

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Matthew Wright

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I'm a New Zealand historian with a life-long interest in matters military, particularly naval engineering. My books have principally been published by Penguin Random House. I'm a Fellow of the Royal Historical Society at University College, London.
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The ‘ Washington Naval Treaty ’ was one of the world’s few successful naval limitation agreements. It was negotiated between November 1921 and February 1922, in Washington, and signed on 6 February that year.

naval treaty

HMS Rodney after refitting at Liverpool, 1942 – a ship built as a direct outcome of the Five Power Treaty signed in Washington twenty years earlier. Public domain, via Wikipedia.

It limited not just numbers of ships, but also the specifications and timing of new-build vessels, but what’s perhaps more interesting is the diplomatic turning and twisting around it – and some of the curious quirks that followed in the terms, along with the actual costs and consequences:

1. ‘Washington Treaty’ is the common term for the agreement. But actually it’s a metonym – the use of a place-name to describe something associated with it, in this case the ‘Conference on the Limitation of Armaments’ held in Washington during the northern winter of 1921-22. The naval document was formally the ‘Five Power Treaty’, sometimes referred to officially as the ‘Washington Naval Treaty’ or ‘Naval Treaty’. It was only one of several agreements reached at the Conference. Other treaties negotiated at the same conference included one between five nations to limit submarines and poison gas; the Pacific Treaty, signed by the British Empire, United States, Japan and France, which replaced the Anglo-Japanese Alliance; the ‘Nine Power Treaty’ relating to customs tariffs in China; and the Shantung Treaty, between China and Japan.

2. Britain sent a team of naval architects to back their delegates Arthur Balfour, Lord Lee of Fareham and Sir Auckland Geddes. This meant the British negotiators could get expert advice more quickly than other parties.

3. The United States had access to other nations’ diplomatic codes, meaning they were able to obtain negotiating details the delegates referred back to their governments, including the Japanese bottom line.

4. The ‘Five Power Treaty’ remains one of the few successful naval arms limitation treaties, (mostly) followed by signatories and never repudiated before expiry.

5. The Treaty definition of ‘standard’ displacement took the form it did because the British didn’t want to reveal the existence of their secret liquid-loaded anti-torpedo system.

6. The Treaty also limited the extent to which heavy ships could be rebuilt – allowing a maximum increase of only 3000 tons, more deck armour, but no new side armour or alteration to main armament. This was to prevent anybody drastically improving the military characteristics.

7. The French version referred to battleships and battlecruisers as ‘ships of the line’; a quirk of language and nomenclature.

8. Existing, planned or under-construction capital ships scheduled for cancellation or scrapping totalled 845,740 tons, of which over 400,000 tons were British. Their agreed scrapping list included two pre-dreadnoughts.

9. Cancellations of part-built ships included US vessels on which the US Navy had spent $332 million to that time (in early 1920s money).

10. Britain was allowed to build two new battleships. However, these had to be to Treaty limits. What the Royal Navy really wanted was two of their planned 48,000-ton ‘G3’ class battlecruisers, but that was turned down.

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Copyright © Matthew Wright 2017



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