View source for London Naval Treaty

{{Short description|1930 international arms control treaty}}
{{For|the 1936 treaty|Second London Naval Treaty}}
{{Use dmy dates|date=May 2017}}
{{Use British English|date=May 2017}}
{{Infobox treaty
| name = London Naval Treaty
| long_name = International Treaty for the Limitation and Reduction of Naval Armament
| image = File:London Naval Conference 1930.jpg
| image_size = 
| alt = 
| caption = Members of the United States delegation en route to the conference, January 1930
| type = [[Arms control]]
| context = [[World War I]]
| date_signed = {{Start date|df=yes|1930|4|22}}
| location_signed = [[London]]
| date_sealed = 
| date_effective = {{Start date|df=yes|1930|10|27}}
| date_expiration = {{End date|df=yes|1936|12|31}} (Except for Part IV)
| mediators = 
| negotiators = * {{flagicon|United Kingdom}}  [[Ramsay MacDonald]] 
* {{flagicon|Empire of Japan}} [[Wakatsuki Reijirō]]
* {{flagicon|French Third Republic}} [[André Tardieu]]
* {{flagicon|United States|1912}} [[Henry L. Stimson]]
* {{flagicon|Kingdom of Italy}} [[Dino Grandi]]
| signatories = * {{flagicon|United Kingdom}} [[George V]]
* {{flagicon|Empire of Japan}} [[Hirohito]]
* {{flagicon|French Third Republic}} [[Gaston Doumergue]]
* {{flagicon|United States|1912}} [[Herbert Hoover]]
* {{flagicon|Kingdom of Italy}} [[Victor Emmanuel III of Italy|Victor Emmanuel III]]
| parties = * {{flag|United Kingdom}}
* {{flagcountry|Empire of Japan}}
* {{flagcountry|French Third Republic|France}}
* {{flag|United States|1912}}
* {{flagcountry|Kingdom of Italy|Italy}}
| ratifiers = 
| depositor = [[United Kingdom of Great Britain and Northern Ireland]]<ref>https://ihl-databases.icrc.org/en/ihl-treaties/submarine-warfare-rules-1930?activeTab=%3C/ref%3E</ref>
| citations = 
| language = [[French language|French]] and [[English language|English]]
| wikisource = London Naval Treaty
}}

The '''London Naval Treaty''', officially the '''Treaty for the Limitation and Reduction of Naval Armament''', was an agreement between the [[United Kingdom]], [[Empire of Japan|Japan]], [[French Third Republic|France]], [[Kingdom of Italy|Italy]], and the [[United States]] that was signed on 22 April 1930. Seeking to address issues not covered in the 1922 [[Washington Naval Treaty]], which had created [[tonnage]] limits for each nation's [[Surface combatant|surface warships]], the new agreement regulated [[submarine warfare]], further controlled cruisers and destroyers, and limited naval shipbuilding.

Ratifications were exchanged in London on 27 October 1930, and the treaty went into effect on the same day, but it was largely ineffective.<ref>John Maurer, and Christopher Bell, eds. ''At the crossroads between peace and war: the London Naval Conference in 1930'' (Naval Institute Press, 2014).</ref>

The treaty was registered in ''[[Treaty series#League of Nations|League of Nations Treaty Series]]'' on 6 February 1931.<ref>''League of Nations Treaty Series'', vol. 112, pp. 66–96.</ref>

==Conference==
[[File:Londonnavalconference2.jpg|thumb|right|Menu and List of Official Toasts at formal dinner which opened the London Naval Conference of 1930]]
The signing of the treaty remains inextricably intertwined with the ongoing negotiations, which began before the official start of the London Naval Conference of 1930, evolved throughout the progress of the official conference schedule, and continued for years afterward.

==Terms==
The treaty was seen as an extension of the conditions agreed in the [[Washington Naval Treaty]], an effort to prevent a naval [[arms race]] after [[World War I]].

The conference was a revival of the efforts that had gone into the 1927 [[Geneva Naval Conference]] at which the various negotiators had been unable to reach agreement because of bad feelings between the British and the American governments. The problem may have initially arisen from discussions held between US President President [[Herbert Hoover]] and UK Prime Minister [[Ramsay MacDonald]] at [[Rapidan Camp]] in 1929, but a range of factors affected tensions, which were exacerbated by the other nations at the conference.<ref>Steiner, Zara S. (2005). [https://books.google.com/books?id=rJ9JJIVmFpkC&q=The+Lights+that+Failed:+European+International+History+1919-1933 ''The Lights that Failed: European International History 1919–1933,'' pp. 587]–591.</ref>

Under the treaty, the [[standard displacement]] of submarines was restricted to 2,000 tons, with each major power being allowed to keep three submarines of up to 2,800 tons except that France was allowed to keep one. The submarine gun caliber was also restricted for the first time to {{convert|6.1|in|0|abbr=on}} with one exception, an already-constructed French submarine being allowed to retain  {{convert|8|in|0|abbr=on}} guns. That put an end to the 'big-gun' submarine concept pioneered by the British [[British M class submarine|M class]] and the French [[Surcouf (N N 3)|''Surcouf'']].

Per the terms of the treaty, Britain, the United States, and Japan reduced their number of capital ships, Japan by one, the United States by three, and Britain by five. Some were scrapped and others converted to auxiliary or training ships.  All of these had been launched prior to WWI, and had smaller guns than most of the ships which were retained.

The treaty also established a distinction between cruisers armed with guns up to {{convert|6.1|in|0|abbr=on}} ("[[light cruiser]]s" in unofficial parlance) from those with guns up to {{convert|8|in|0|abbr=on}} ("[[heavy cruiser]]s"). The number of heavy cruisers was limited: Britain was permitted 15 with a total tonnage of 147,000, the Americans were permitted 18, totalling 180,000, and the Japanese were permitted 12, totalling 108,000 tons. For light cruisers, no numbers were specified but tonnage limits were 143,500 tons for the Americans, 192,200 tons for the British, and 100,450 tons for the Japanese.<ref>{{cite web|last=U.S. Department of State|title=The London Naval Conference, 1930|url=https://history.state.gov/milestones/1921-1936/london-naval-conf|access-date=20 March 2014}}</ref>

Destroyer tonnage was also limited, with destroyers being defined as ships of less than 1,850 tons and guns up to {{convert|5.1|in|0|abbr=on}}. The Americans and the British were permitted up to 150,000 tons and Japan 105,500 tons.

Article 22 relating to submarine warfare declared [[international law]] applied to them as to surface vessels.<ref>{{cite magazine |last=Fink |first=Martin|date=February 2014 |title=De onderzeeboot in het oorlogsrecht |url=https://marineblad.nl/images/Marineblad/2010-2019/2014/Marineblad%201%20februari%202014.pdf|magazine=Marineblad |volume=124 |issue=1 |pages=22-25|language=Dutch}}</ref> Also, merchant vessels that demonstrated "persistent refusal to stop" or "active resistance" could be sunk without the ship's crew and passengers being first delivered to a "place of safety".<ref>{{Cite web |url=http://www.icrc.org/ihl.nsf/FULL/310?OpenDocument |title=Treaty for the Limitation and Reduction of Naval Armaments, (Part IV, Art. 22, relating to submarine warfare). London, 22 April 1930 |access-date=13 March 2006 |archive-date=31 July 2012 |archive-url=https://web.archive.org/web/20120731025604/http://www.icrc.org/ihl.nsf/FULL/310?OpenDocument |url-status=dead }}</ref>

Article 8 outlined smaller surface combatants. Ships between 600 and 2,000 tons, with guns not exceeding {{convert|6|in|0|abbr=on}} with a maximum of four gun mounts above {{convert|3|in|0|abbr=on}} without torpedo armament and up to {{convert|20|kn|km/h|0|abbr=on}}, were exempt from tonnage limitations. The maximum specifications were designed around the French [[Bougainville-class aviso]]s, which were in construction at the time.{{cn|date=February 2023}}

Warships under 600 tons were also completely exempt. That led to creative attempts to use the unlimited nature of the exemption with the Italian [[Spica-class torpedo boat]]s, Japanese [[Chidori-class torpedo boat]]s, French [[La Melpomène-class torpedo boat]]s and British [[Kingfisher-class sloop]]s.<ref>{{cite book |last1=John |first1=Jordan |title=Warship 2016 |publisher=Conway |isbn=978-1-84486-326-6 |pages=8–10 |ref=Warship 2016|date=13 September 2016}}</ref>

==Aftermath==
The next phase of attempted naval arms control was the [[Second Geneva Naval Conference]] in 1932. Active negotiations among the other treaty signatories continued during the following years.<ref>[https://www.nytimes.com/1934/06/09/archives/naval-men-see-hull-on-the-london-talks-admiral-leigh-and-commander.html "Naval Men See Hull on the London Talks; Admiral Leigh and Commander Wilkinson Will Sail Today to Act as Advisers"]. ''[[The New York Times|New York Times]].'' 9 June 1934.</ref>

That was followed by the [[Second London Naval Treaty]] of 1936.

==See also==
*[[Treaty for the Limitation of Naval Armament]]
*[[Washington Naval Treaty]]
*[[Second London Naval Treaty]] – List of treaties signed in London.
*[[Treaty of London (disambiguation)|Treaty of London]] – List of treaties signed in London.
*[[May 15 Incident]] – attempted coup in Japan

==Notes==
{{Reflist}}

==Further reading==
* {{cite journal|last1=Baker|first1=A. D. III|year=1989 |title=Battlefleets and Diplomacy: Naval Disarmament Between the Two World Wars|journal=Warship International|volume=XXVI |issue=3 |pages=217–255 |issn=0043-0374}}
* Dingman, Roger. ''Power in the Pacific: The Origins of Naval Arms Limitation, 1914–1922'' (1976)
* Goldstein, Erik, and John H. Maurer, eds. ''The Washington Conference, 1921–22: Naval Rivalry, East Asian Stability and the Road to Pearl Harbor'' (Taylor & Francis, 1994).
* Maurer, John, and Christopher Bell, eds. ''At the Crossroads between Peace and War: The London Naval Conference in 1930'' (Naval Institute Press, 2014).
* Redford, Duncan. "Collective Security and Internal Dissent: The Navy League's Attempts to Develop a New Policy towards British Naval Power between 1919 and the 1922 Washington Naval Treaty." ''History'' 96.321 (2011): 48–67.
* Roskill, Stephen. ''Naval Policy Between Wars. Volume I: The Period of Anglo-American Antagonism 1919–1929'' (Seaforth Publishing, 2016).
* Steiner, Zara S. (2005). [https://books.google.com/books?id=rJ9JJIVmFpkC&q=The+Lights+that+Failed:+European+International+History+1919-1933  ''The Lights that Failed: European International History 1919–1933.''] Oxford: [[Oxford University Press]]. {{ISBN|978-0-19-822114-2}}; [http://www.worldcat.org/wcpa/oclc/58853793  OCLC 58853793]

==External links==
*[http://www.navweaps.com/index_tech/tech-089_London_Treaty_1930.php Text of the treaty]

{{Interwar Naval Arms Limitation|state=expanded}}
{{Herbert Hoover}}
{{Ramsay MacDonald|state=collapsed}}
{{Authority control}}

[[Category:1930 in France]]
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