Editing Submarine (section)

===Military===
{{main|Submarine warfare|Attack submarine|Ballistic missile submarine|Cruise missile submarine|Nuclear submarine}}
[[File:German UC-1 class submarine.jpg|thumb|German [[German Type UC I submarine|''UC-1''-class]] World War I submarine. The wires running up from the bow to the conning tower are the [[jumping wire]]s]]
[[File:Allveelaev Lembit 2012.jpg|thumb|{{ship|EML|Lembit||6}} in the [[Estonian Maritime Museum]]. The ''Lembit'' is the only minelayer submarine of its series left in the world.<ref>{{cite news|title=World's oldest submerged submarine reaches land|author=Mattias, L.|url=http://ireport.cnn.com/docs/DOC-615075|work=CNN|date=30 May 2011|access-date=29 January 2013|archive-date=4 March 2016|archive-url=https://web.archive.org/web/20160304054336/http://ireport.cnn.com/docs/DOC-615075|url-status=dead}}</ref>]]

Before and during [[World War II]], the primary role of the submarine was anti-surface ship warfare. Submarines would attack either on the surface using deck guns, or submerged using [[torpedo]]es. They were particularly effective in sinking Allied transatlantic shipping in both World Wars, and in disrupting Japanese supply routes and naval operations in the Pacific in World War II.

[[Naval mine|Mine]]-laying submarines were developed in the early part of the 20th century. The facility was used in both World Wars. Submarines were also used for inserting and removing covert agents and military forces in [[special operations]], for intelligence gathering, and to rescue aircrew during air attacks on islands, where the airmen would be told of safe places to crash-land so the submarines could rescue them. Submarines could carry cargo through hostile waters or act as supply vessels for other submarines.

Submarines could usually locate and attack other submarines only on the surface, although {{HMS|Venturer|P68|6}} managed to sink {{GS|U-864||2}} with a four torpedo spread while both were submerged. The British developed a specialized anti-submarine submarine in WWI, the [[British R-class submarine|R class]]. After WWII, with the development of the homing torpedo, better [[sonar]] systems, and [[nuclear propulsion]], submarines also became able to hunt each other effectively.

The development of [[submarine-launched ballistic missile]] and submarine-launched [[cruise missile]]s gave submarines a substantial and long-ranged ability to attack both land and sea targets with a variety of weapons ranging from [[cluster bomb]]s to [[nuclear weapon]]s.

The primary defense of a submarine lies in its ability to remain concealed in the depths of the ocean. Early submarines could be detected by the sound they made. Water is an excellent conductor of sound (much better than air), and submarines can detect and track comparatively noisy surface ships from long distances. Modern submarines are built with an emphasis on [[Stealth technology|stealth]]. Advanced [[propeller]] designs, extensive sound-reducing insulation, and special machinery help a submarine remain as quiet as ambient ocean noise, making them difficult to detect. It takes specialized technology to find and attack modern submarines.

[[File:Trident II D5 launches from the USS Nebraska (SSBN 739), March 26, 2008.jpg|right|thumb|[[UGM-133 Trident II|Trident II D5]] is one of the most advanced [[submarine-launched ballistic missile]]s]]
[[Sonar#Active sonar|Active sonar]] uses the reflection of sound emitted from the search equipment to detect submarines. It has been used since WWII by surface ships, submarines and aircraft (via dropped buoys and helicopter "dipping" arrays), but it reveals the emitter's position, and is susceptible to counter-measures.

A concealed military submarine is a real threat, and because of its stealth, can force an enemy navy to waste resources searching large areas of ocean and protecting ships against attack. This advantage was vividly demonstrated in the 1982 [[Falklands War]] when the British [[nuclear-powered]] submarine {{HMS|Conqueror|S48|6}} sank the Argentine cruiser {{ship|ARA|General Belgrano||2}}. After the sinking the Argentine Navy recognized that they had no effective defense against submarine attack, and the Argentine surface fleet withdrew to port for the remainder of the war. An Argentine submarine remained at sea, however.<ref>{{cite book |last = Finlan |first = Alastair |title = The Royal Navy in the Falklands Conflict and the Gulf War: Culture and Strategy |publisher = Psychology Press |series = British Politics and Society |volume = 15 |date = 2004 |location = London |pages = 214 |url = https://books.google.com/books?id=TmP27lCid8AC&q=general+belgrano+naval+strategy&pg=PA84 |isbn = 978-0-7146-5479-9 }}</ref>