United States Navy

===Operating forces===
{{main|List of units of the United States Navy}}
{{further|Structure of the United States Navy#Numbered fleets}}
[[File:USN Fleets (2009).png|alt=Areas of responsibility for each of the United States Navy Fleets.|thumb|Areas of responsibility for each of the United States Navy fleets. [[United States Tenth Fleet|Tenth Fleet]] serves as the numbered fleet for [[U.S. Fleet Cyber Command]] and therefore is not shown.]]

There are nine components in the operating forces of the U.S. Navy: the [[United States Fleet Forces Command]] (formerly United States Atlantic Fleet), [[United States Pacific Fleet]], [[United States Naval Forces Central Command]], [[United States Naval Forces Europe]], [[Naval Network Warfare Command]], [[United States Navy Reserve|Navy Reserve]], [[United States Naval Special Warfare Command]], and [[Operational Test and Evaluation Force]]. Fleet Forces Command controls a number of unique capabilities, including [[Military Sealift Command]], [[Naval Expeditionary Combat Command]], and [[U.S. Naval Information Forces|Naval Information Forces]].

The United States Navy has seven active numbered fleets&nbsp;– [[United States Second Fleet|Second]], [[United States Third Fleet|Third]], [[United States Fifth Fleet|Fifth]], [[United States Sixth Fleet|Sixth]], [[United States Seventh Fleet|Seventh]] and [[United States Tenth Fleet|Tenth Fleets]] are each led by a [[Vice admiral (United States)|vice admiral]], and the [[United States Fourth Fleet|Fourth Fleet]] is led by a [[Rear admiral (United States)|rear admiral]]. These seven fleets are further grouped under Fleet Forces Command (the former Atlantic Fleet), Pacific Fleet, Naval Forces Europe-Africa, and Naval Forces Central Command, whose commander also doubles as Commander Fifth Fleet; the first three commands being led by four-star admirals. The [[United States First Fleet]] existed after World War II from 1947, but it was redesignated the Third Fleet in early 1973. The Second Fleet was deactivated in September 2011 but reestablished in August 2018 amid heightened tensions with Russia.<ref>{{Cite news|url=https://www.cnn.com/2018/05/04/politics/us-navy-second-fleet-russia-tensions/index.html|title=US Navy re-establishes Second Fleet amid Russia tensions|first=Ryan |last=Browne|work=CNN|access-date=16 November 2018|archive-url=https://web.archive.org/web/20181030231709/https://www.cnn.com/2018/05/04/politics/us-navy-second-fleet-russia-tensions/index.html|archive-date=30 October 2018|url-status=live}}</ref> It is headquartered in Norfolk, Virginia, with responsibility over the East Coast and North Atlantic.<ref>{{Cite news|url=https://www.navy.mil/submit/display.asp?story_id=106837|title=Navy Establishes U.S. 2nd Fleet, Vice Adm. Lewis Assumes Command|last=Affairs|first=This story was written by U.S. Fleet Forces Public|access-date=16 November 2018|language=en|archive-url=https://web.archive.org/web/20181005112023/https://www.navy.mil/submit/display.asp?story_id=106837|archive-date=5 October 2018|url-status=live}}</ref> In early 2008, the Navy reactivated the Fourth Fleet to control operations in the area controlled by Southern Command, which consists of US assets in and around Central and South America.<ref>{{cite news |url=http://www.navy.mil/search/display.asp?story_id=36606 |title=Navy Reestablishes U.S. Fourth Fleet |work=Navy News Service |date=24 April 2008 |last=Gragg |first=Alan |id=NNS080424-13 |access-date=30 April 2008 |archive-url=https://web.archive.org/web/20080502014504/http://www.navy.mil/search/display.asp?story_id=36606 |archive-date=2 May 2008 }}</ref> Other number fleets were activated during World War II and later deactivated, renumbered, or merged.