The Five-Power Treaty, also known as the Washington Naval Treaty, was an agreement reached at the Washington Conference (1921-2) to limit tonnage of certain types of naval ships and establish a ratio of capital ships for each nation.  The ratio was 5 for the United Kingdom, 5 for the United States, 3 for Japan, 1.67 for France, and 1.67 for Italy.

• France
• Italy
• Japan
• The United Kingdom
• The United States