Editing Battleship (section)

== Inter-war period ==
[[File:HMS Nelson (1931) profile drawing.png|thumb|left|Profile drawing of {{HMS|Nelson|28|6}} commissioned 1927]]

In the immediate aftermath of the war, the most modern units of the German fleet was interned at [[Scapa Flow]], where in June 1919, their crews [[scuttling of the German fleet at Scapa Flow|scuttled the fleet]] to avoid it being handed over to the Allies. The remaining dreadnoughts still in German ports were therefore seized as compensation for the scuttled ships. The postwar {{lang|de|[[Reichsmarine]]}} of [[Weimar Germany]] was limited to a contingent of eight old pre-dreadnoughts (of which two would be kept in [[reserve fleet|reserve]]) under the terms of the [[Treaty of Versailles]]; new battleships were subject to severe restrictions on size and armament.{{sfn|Gardiner|Chesneau|1980|p=218}} The surviving battleships of Austria-Hungary, the other defeated Central Power, were soon distributed among the Allies, to be broken up.{{sfn|Gardiner|Gray|1985|p=329}}

While the other major naval powers remained free to build new battleships, most of them were financially crippled after the war. The prospect of a renewed naval arms race between the United States, United Kingdom, and Japan, appealed to few politicians in the three countries, and so they concluded the [[Washington Naval Treaty]] in 1922, which also included Italy and France. The treaty limited the number and size of battleships, and imposed a ten-year building holiday, along with other provisions. The treaty also imposed a ratio of 5:5:3 on total displacement of battleships for the US, UK, and Japan, respectively, and it severed the [[Anglo-Japanese Alliance]].{{sfn|Friedman|1984|pp=181–182}}{{sfn|Gardiner|Chesneau|1980|pp=2, 90, 167, 255, 280}}{{sfn|Kennedy|1983|p=277}} The only exceptions to the building holiday were for the two British {{sclass|Nelson|battleship|1}}s, which were permitted to give Britain parity with the latest American and Japanese battleships, which were all armed with {{convert|16|in|adj=on|0}} guns.{{sfn|Gardiner|Chesneau|1980|p=2}}

The Washington treaty was followed by a series of other naval treaties, including the [[London Naval Treaty|First London Naval Treaty]] (1930) and the [[Second London Naval Treaty]] (1936), which both set additional limits on major warships.{{sfn|Ireland|Grove|1997|pp=124–126, 139–142}} The treaty limitations meant that fewer new battleships were launched in 1919–1939 than in 1905–1914. The treaties also inhibited development by imposing upper limits on the weights of ships. Designs like the projected British {{sclass2|N3|battleship|2}}, the first American {{sclass|South Dakota|battleship|4||1920}}, and the Japanese {{sclass|Kii|battleship|4}}—all of which continued the trend to larger ships with bigger guns and thicker armor—never got off the drawing board. Those designs which were commissioned during this period were referred to as [[treaty battleship]]s.{{sfn|Sumrall|1992|pp=25–28}} The collapse of the treaty system began during the negotiations for the Second London Treaty, where Japan demanded parity with Britain and the US, which the latter two flatly rejected. Japan withdrew from the treaty system in 1936, though the agreements remained in effect until January 1937.{{sfn|Evans|Peattie|1997|pp=297–298}}

=== Rise of air power ===
[[File:Ostfriesland bombed by Mitchells team p19.jpg|thumb|Bombing tests which sank {{SMS|Ostfriesland}} (1909), September 1921]]

As early as 1914, the British Admiral [[Percy Scott]] predicted that battleships would soon be made irrelevant by [[military aviation|aircraft]].{{sfn|Kennedy|1983|p=199}} Between 1916 and 1918, US Admiral [[William Fullam]] published a series of papers stating that aircraft would become an independent strike arm of the fleet, and argued that the {{sclass|Lexington|battlecruiser|1}}s then under construction should be converted to [[aircraft carrier]]s than scrapped.{{sfn|Hone|Friedman|Mandeles|1999|pp=25–26}} By the end of World War I, aircraft had successfully adopted the torpedo as a weapon. In 1921 the Italian general and air theorist [[Giulio Douhet]] completed a hugely influential treatise on strategic bombing titled ''The Command of the Air'', which foresaw the dominance of air power over conventional military and naval forces.{{sfn|Budiansky|1998|pp=136–137}}

In 1921, US General [[Billy Mitchell]] used the ex-German dreadnought {{SMS|Ostfriesland}} in a series of bombing tests conducted by the Navy and Army. The test involved a series of attacks on the stationary, unmanned ships using low-level, land-based bombers dropping bombs that ranged from {{convert|550|to|2000|lb}}. ''Ostfriesland'' was sunk by the heaviest bombs, though Mitchell broke the rules of the tests and the subsequent report concluded that had the ship been crewed, underway, and firing back at the aircraft, damage control teams aboard ''Ostfriesland'' could have managed any damage inflicted. Mitchell and his supporters nevertheless embarked on a public campaign that falsely claimed that ''Ostfriesland'' was a super-battleship, and the quick sinking proved that battleships were obsolete. Mitchell would eventually be subjected to a [[court martial]], convicted, and discharged from the Army over his insubordinate tactics.{{sfn|Budiansky|1998|pp=147–151}}

Naval aviation traces its origin back to the first decade of the 20th century, though early efforts were based on using aircraft to scout for the fleet and help direct gunfire at long range. A number of experimental aircraft carriers were employed during World War I, primarily by the Royal Navy, all converted from merchant vessels or existing warships. The US Navy completed its first carrier, {{USS|Langley|CV-1|6}}, in 1922. But aircraft carriers in the 1920s faced a number of challenges to be overcome: aircraft of the day were short-ranged, which meant the carrier had to be very close to the enemy to be able to launch and then recover a strike, which exposed the carriers to attack. In addition, the available planes had insufficient power to carry meaningful bomb loads. Early naval aviators nevertheless pioneered effective tactics like [[dive bombing]] during this period.{{sfn|Gardiner|Gray|1985|pp=64–71, 120}}{{sfn|Hone|Friedman|Mandeles|1999|pp=13–15, 41–43}}

=== Fast battleships and the end of the treaty system ===
[[File:Italian battleship Vittorio Veneto.jpg|thumb|The Italian fast battleship {{ship|Italian battleship|Vittorio Veneto||2}}]]

Because the Washington Treaty system precluded the construction of any new battleships until the early 1930s, the major naval powers began a program of modernization for their most effective battleships. Britain conducted a series of refits to their ''Queen Elizabeth''-class battleships through the 1920s, adding [[anti-torpedo bulge]]s, additional anti-aircraft guns, and [[aircraft catapult]]s; further refits in the 1930s increased armor protection and further strengthened their anti-aircraft batteries. The {{sclass|Revenge|battleship|1}}s were less heavily modified during the period. The US {{sclass|Florida|battleship|5}}, {{sclass|Wyoming|battleship|4}}, and {{sclass|New York|battleship|4}}es received similar treatments in the 1920s, while the ''Nevada|'' and {{sclass|Pennsylvania|battleship|5}}es received new turbines, additional armor, and more anti-aircraft guns. The Japanese similarly updated their ''Fusō'', {{sclass|Ise|battleship|5}}, and {{sclass|Nagato|battleship|1}}s, and rebuilt three of the four {{sclass|Kongō|battlecruiser|1}}s into fast battleships, albeit with significantly inferior protection compared to the other ships. They all also received distinctive [[pagoda mast]]s. {{ship|Japanese battleship|Hiei||2}} was initially disarmed to serve as a [[training ship]] under the terms of the Washington Treaty, but was remilitarized in the late 1930s. In the 1930s, all four classes were lengthened and had their propulsion systems improved to increase their speeds.{{sfn|Gardiner|Chesneau|1980|pp=7–8, 91, 168, 171–173}}

The French and Italian navies were exempted from the 10-year building holiday, owing to the comparative obsolescence of their battleships; they were permitted to build {{cvt|70000|LT|lk=on}} worth of battleships. But the weak economies of both countries led both to defer new construction until Germany began building the {{sclass|Deutschland|cruiser|4}} of heavily armed cruiser at the end of the 1920s. This prompted the French to build the {{sclass|Dunkerque|battleship|4}} of small, fast battleships armed with {{cvt|330|mm|in|order=flip}} guns, which led to a short arms race in Europe in the mid-1930s. The Italians responded with the significantly larger and more powerful {{sclass|Littorio|battleship|4}}, armed with 15-inch guns. The French, in turn, began the {{sclass|Richelieu|battleship|1}}s to counter the ''Littorio''s.{{sfn|Jordan|Dumas|2009|pp=15–21, 29–31}} By this time, [[Nazi Germany]] had signed the [[Anglo-German Naval Agreement]] in 1935, which removed the restrictions imposed by Versailles and pegged German naval strength to 35% of British tonnage. This permitted the construction of two {{sclass|Scharnhorst|battleship|1}}s, which were also a response to the ''Dunkerque''s. The advent of the ''Richelieu''s prompted the Germans to build the two {{sclass|Bismarck|battleship|1}}s late in the decade.{{sfn|Garzke|Dulin|1985|pp=128, 204–205}} The Germans thereafter embarked on the ambitious [[Plan Z]] naval construction program, which included a total of eight battleships, of which the ''Bismarck''s would be the first two.{{sfn|Gardiner|Chesneau|1980|p=220}}

Against the backdrop of European rearmament in the mid-1930s, Britain began planning its first battleship class in a decade: the {{sclass|King George V|battleship|4||1939}}. These were armed with 14-inch guns intended to comply with the terms of the Second London Naval Conference, and they were laid down in 1937. The United States began their {{sclass|North Carolina|battleship|4}} at the same time, and though they were intended to be armed with 14-inch guns, Japan's refusal to agree to the Second London Treaty led the US to invoke a clause of the treaty that allowed an increase to 16-inch guns. In 1939, these were followed by the four {{sclass|South Dakota|battleship|1||1939}}s, and in 1940 by the first of four {{sclass|Iowa|battleship|1}}s.{{sfn|Gardiner|Chesneau|1980|pp=15, 97–99}} For its part, Japan had decided to embark on a program of four very large {{sclass|Yamato|battleship|1}}s, armed with {{convert|18|in|adj=on|0}} guns, as early as 1934,{{sfn|Evans|Peattie|1997|p=295}} though work did not begin on the first ship until late 1937.{{sfn|Gardiner|Chesneau|1980|p=178}}