Agreement between the United Kingdom, Japan, France, Italy and the United States, signed on 22 April 1930, which regulated submarine warfare and limited naval shipbuilding
The London Naval Treaty of 1930 extended naval arms limitations to submarines and smaller warships, though it ultimately proved largely ineffective.
Key Facts
- Date Signed
- 22 April 1930
- Date In Force
- 27 October 1930
- Signatory Nations
- 5 (UK, Japan, France, Italy, USA)
- Preceded By
- Washington Naval Treaty, 1922
- League of Nations Registration
- 6 February 1931
By the Numbers
Location
Cause → Event → Consequence
The 1922 Washington Naval Treaty had established tonnage limits for major surface warships but left significant gaps, particularly regarding submarines, cruisers, and destroyers. The major naval powers sought a follow-on agreement to address these omissions and further constrain the arms race at sea.
Representatives of the United Kingdom, Japan, France, Italy, and the United States signed the London Naval Treaty on 22 April 1930. The agreement regulated submarine warfare, imposed additional controls on cruisers and destroyers, and set limits on overall naval shipbuilding beyond those established at Washington in 1922.
Ratifications were exchanged in London on 27 October 1930, bringing the treaty into force that same day. It was registered with the League of Nations on 6 February 1931. Despite these formalities, the treaty was largely ineffective in restraining naval expansion among the signatory powers in the years that followed.
Political Outcome
Treaty signed and ratified; went into force 27 October 1930, but was largely ineffective in limiting naval armament.