Command of the sea

"Sea power" redirects here. For other uses, seeSea power (disambiguation).

Command of the sea(also calledcontrol of the seaorsea control) is a naval military concept regarding the strength of a particularnavyto a specific naval area it controls. A navy has command of the sea when it is so strong that its rivals cannot attack it directly. This dominance may apply to its surrounding waters (i.e., thelittoral) or may extend far into the oceans, meaning the country has ablue-water navy.It is the naval equivalent ofair supremacy.

USSAbraham Lincoln,aUnited States Navyaircraft carrier,a means of global maritimepower projection

With command of the sea, a country (or alliance) can ensure that its own military and merchant ships can move around at will, while its rivals are forced either to stay in port or to try to evade it. It also enables free use ofamphibious operationsthat can expand ground-based strategic options. The BritishRoyal Navyheld command of the sea for most ofthe periodbetween the 18th to the early 20th centuries, allowing Britain and its allies to trade and to move troops and supplies easily in wartime, while its enemies could not. In the post-World War IIperiod, theUnited States Navyhas had command of the sea.

Few navies can operate as blue-water navies, but "many States are convertinggreen-water naviesto blue-water navies and this will increase military use of foreignExclusive Economic Zones[littoral zone to 200 nautical miles (370 km)] with possible repercussions for the EEZ regime. "

Historic command of the sea during the age of sail

Britannia rule the waves:decorated plate made in Liverpool circa 1793-1794 (Musée de la Révolution française).

National capabilities

Historically, many powers attempted to extend command of the sea into peacetime, imposing taxes or other restrictions on shipping using areas of open sea. For example,Veniceclaimed theAdriatic Sea,and exacted a heavy toll from vessels navigating itsnorthern waters.GenoaandFranceeach claimed portions of the westernMediterranean Sea.DenmarkandSwedenclaimed to share theBaltic Seabetween them.Spainclaimed dominion over thePacific Oceanand theGulf of Mexico,andPortugalover theIndian Oceanand all theAtlantic Oceansouth ofMorocco(Hall, 148-9).

Asymmetric countermeasures

During theage of sail,there were two primary counter measures to another power holding control of the sea:smuggling,andprivateering.Smuggling helped to ensure that a country could continue trading (and obtaining food and other vital supplies) even when under blockade, while privateering allowed the weaker power to disrupt the stronger power's trade. As these measures, which are examples ofasymmetric warfare,came from non-governmental and sometimes criminal organizations, they fell into disfavor with stronger governments. The 1856Paris Declaration Respecting Maritime Lawbanned privateering. That treaty was ratified by relatively few countries, but has become the customary law of the sea.

Historic command of the sea in the era of steam

A more modern countermeasure, similar to privateering, was the use ofsubmarine warfareby Germany duringWorld War IandWorld War IIto attack allied merchant shipping primarily in theAtlantic Ocean,Mediterranean Sea,andBaltic Sea.

Historic command of the sea in the era of naval aviation

DuringWorld War II,aircraftalso became an effective countermeasure to command of the sea, since ships could not defend themselves well against air attack. TheBattle of Britainwas largely an attempt by Germany to eliminate theRoyal Air Force,so that it would not be able to defend theRoyal Navyfrom air attack and even to allow amaritime invasion of Great Britain proper.The entire Japanese naval strategy during World War II in the Pacific was to acquire command of the sea by largescale destruction of Allied naval power, until their fleet was either destroyed or rendered irrelevant by theBattle of Leyte Gulfgiving command of the sea to the Allies.

Modern command of the sea

HMSDaring,aRoyal NavyType 45guided missile destroyer

Advanced navies, with access tosurveillance satellitesand large-scale submarine detection systems, can rarely be surprised at sea, but cannot be everywhere. Individual ships of advanced navies can be vulnerable at sea (e.g., theUSSStarkhit by anIraqiaircraft-delivered anti-ship missile while patrolling thePersian Gulf) or in port (e.g., by thesuicide attackon theUSSCole.)

"Blue-water"naval capabilitymeans that a fleet is able to operate on the "high seas."While traditionally a distinction was made between the coastalbrown-water navy,operating in thelittoral zoneto 200 nautical miles (370 km), and a seagoing blue-water navy, a new term, "green-water navy,"has been created by the U.S. Navy,which refers to the coastal submarines and fast attack boats of many nations, the larger littoral combat corvettes and similar vessels of a substantial number of powers, and amphibious vessels ranging from elderlyLSTsto complex S/VTOL carriers and other specialized ships.

In modern warfare blue-water navy implies self-contained force protection from sub-surface, surface and airborne threats and a sustainable logistic reach, allowing a persistent presence at range. In some maritime environments such a defence is given by natural obstacles, such as theArcticice shelf.

TheUS Navystudied a concept for an economically priced ship capable of surface and subsurface sea control with ASW helicopters and STOVL fighters for light air defense but not large enough to be well suited to power projection known as aSea Control Ship.This small aircraft carrier was not built by the US although a long deckAmphibious assault shipequipped with STOVL fighters and ASW helicopters instead of its primary transport helicopters is operating in a secondary sea control role.

Requirements for modern sea control

During theFalklands War,the British lacked long-rangeAirborne Warning and Control System(AWACS), which led to ship losses and major damage to others, when theArgentinianattack aircraft came into the view of ship radar at approximately the same time they would fire antiship missiles, and only a short time before they made bombing attacks. A number of navies have learned this lesson. Many navies withSTOVLcarriers have developed helicopter-mounted AWACS like the British and SpanishWestland Sea King AEW,ItalianEH-101 AEW,and the RussianKa-31 AEW helicopter.Recently the French with a new larger CATOBARaircraft carrierobtained the USE-2 HawkeyeAWACS aircraft.

An example for the difference between a blue-water navy and a green-water navy: "...The first should be a 'green-water active defense' that would enable thePeople's Liberation Army Navyto protectChina'sterritorial waters and enforce its sovereignty claims in theTaiwan Straitand theSouth China Sea.The second phase would be to develop a blue-water navy capable of projecting power into the western Pacific... Liu [commander in chief of the PLAN 1982-88 and vice chairman of theCentral Military Commission1989-97] believed that in order to fulfill a blue-water capability, the PLAN had to obtain aircraft carriers... "Aircraft carriersare deployed with other specialized vessels incarrier battle groups,providing protection against sub-surface, surface and airborne threats.

As there is no clear definition of a blue-water navy, the status is disputed. Given the importance of naval aviation, the term may be considered to be strongly linked to the maintenance of aircraft carriers capable of operating in the oceans. "In the early 80s there was a bitter and very public battle fought over whether or not to replaceAustralia's last aircraft carrier,HMASMelbourne.SeniorRoyal Australian Navypersonnel warned without a carrier, Australia would be vulnerable to all types of threat. One ex-Chief of Navy went so far as to claim that we "(the Australians)" would no longer have a blue-water navy (one capable of operating away from friendly coasts). "Yet although theRoyal Thai Navyoperates a sea-going carrier, the RTN is not absolutely a "blue-water navy."

Countermeasures to imposed command

While ablue-water navycan project sea control power into another nation's littoral, it remains susceptible to threats from less capable forces. Sustainment and logistics at range yield high costs and there may be a saturation advantage over a deployed force through the use of land-based air orsurface-to-surface missileassets (whether on terrain-following or ballistic trajectories),diesel-electric submarines,or asymmetric tactics such as Fast Inshore Attack Craft. An example of this vulnerability was the October 2000USSColebombinginAden.In response to these threats, the U.S. Navy has developed theLittoral Combat Ship(LCS).

See also

• Battleplan(documentary TV series)
• Air supremacy
• Naval blockade
• Sea denial
• Alfred Thayer Mahan
• Maritime republics
• Maritime power
• Thalassocracy

References

Sources

• WE Hall,Treatise on International Law,4th ed., 1895.