Julian Corbett states: “The object of naval warfare is the control of communications.”[1] This refers to the control of critical sea lanes; the ability to either move or prevent the movement of men, supplies, and goods is the fundamental mission of naval operations. Sweeping rival naval powers from the seas, Alfred Thayer Mahan’s much vaunted attainment of “Sea Power” is only productive as an intermediate goal. Thus, the goal of naval strategy is either to disrupt enemy trade or to facilitate the transit of force and fire power.

There are two extant strategies for depriving an enemy of supplies and trade: the blockade and guerre de course. Traditional warfare simply accepted the capture of enemy merchants for profit and to apply strategic pressure. Eventually, the centuries-long struggle between the British and the French resulted in the codification of these methods. The fundamental difference between guerre de course and blockading an opponent is the totality with which these strategies can isolate a state from the sea. Warships are excellent platforms for the establishment of naval dominance but they are ill suited for blockade enforcement or campaigns of guerre de course; their limited endurance, small crews, and expense make coverage by a professional naval force difficult to maintain. Historically, the best platform for capturing an opponent’s commerce is the naval auxiliary or privateer. Naval auxiliaries and privateers provide rapid, flexible responses to major threats and have historically allowed states to quickly generate forces sufficient to conduct the critical elements of maritime warfare.

The Essentials of Private Men of War

Traditional state navies are expensive endeavors. Warships are typically built for speed and firepower, take a long time to build, and are hard to justify in peace time. As a result, states tend to make the minimum investment necessary to meet their immediate strategic needs. However, major naval conflict and the demand for platforms has prompted states to expand their fleets rapidly and creatively. Historically this has been done through the issuance of Letters of Marque, and recently this has involved the military activation of civilian ships.

From the 15th to 19th centuries it was common to supplement regular naval forces with irregular units—referred to as privateers. These platforms were privately funded and typically were converted merchantmen. Using Letters of Marque or Reprisal as grants of legitimacy, privateers operated against an enemy’s commerce and, when incentivized through bounties, enemy warships. The Letters granted them state sanction and authority as well as combatant status, preventing captured privateers from being hung as pirates. Enemy merchants, or prizes, were brought to friendly ports and sold when captured. Investors and crews were then paid a portion of prize money garnered from captured enemy merchantmen. Thus, states could readily supplement their regular naval forces at little to no cost.

Privateers were designed to capture merchantmen and had several advantages over their regular counterparts in maritime warfare. They were cheaper to build because merchants did not require a significant amount of firepower to capture privateers and did not need to be built to the same specifications as warships. Most privateers were converted merchantmen and traded normally during peacetime. They also tended to have large crews; this allowed them to continue operating while dispatching men to act as prize crews.[2] Conversely, modern warships tend to be minimally manned and, consequently, suffer operational degradations when not fully manned. Finally, as they were only paid when successful, privateers and privateer crews had strong incentives for mission accomplishment. Many of these factors remain constant today.

A 20th century parallel to the earlier privateer is the naval auxiliary. Taking form in the waning years of the 19th century, these ships saw extensive use during the world wars. In peace-time they were civilian owned and operated, turning their owners a profit while remaining available for combat. Merchant ships of a variety of classes were built to serve combat roles in war time and operated extensively during both wars.

Privateering: The Emergence of a Staple of Warfare and its Subsequent Fall from Grace

The practice of commerce raiding and piracy is nearly as old as merchant shipping, and its official sanction began in the middle ages.[3] An early example of pre-modern privateering dates to 1295 when Bernard Dongresilli, despite his status as a civilian, was authorized to capture Portuguese goods to compensate for his commercial losses to Portuguese raiders.[4] Letters of Reprisal like these were intended to compensate merchants for goods lost to conducted by pirates operating out of hostile states.[5] Eventually, the Letter of Reprisal became the Letter of Marque and was used offensively. Henry VIII used privateers extensively in his wars with the French and they became a staple of maritime conflict for the latter half of the second millennium.[6]

Queen Elizabeth pursued an active regular and irregular naval campaign against Catholic Spain and privateers made up a sizeable portion of her forces. The official state navy, known today as the Royal Navy, was the property of the Queen and was relatively small, designed mostly as a defensive tool. It was tasked with preventing a hostile Spanish landing. Her offensive war with Spain relied heavily on her use of privateers like Drake, Hawkins, Frobisher, and the like, but she was far from the only leader to employ irregular naval units.[7] The French Huguenots and the Dutch rebels also licensed privateering raids against their common Spanish enemy.[8] Guerre de course, a strategy resting solely on private and professional commerce raiding, entered the lexicon as an official strategic term under Louis XIV during a prolonged war with the British.[9] It proved extremely effective and wrought havoc on the British economy despite their theoretical “sea control.”[10]

In the 18th and early 19th centuries privateering was a fixture of weak and strong navies. The British employed privateers extensively against the French; despite the Royal Navy’s strength, at one point 30 percent of the British fleet was privately owned.[11] The contested nature of the sea during the American Revolutionary War, and the number of combatants engaging in maritime trade meant that privateering was both profitable and necessary. In the wars from 1744-1783 British Privateers were prolific and effective, and the profitability of the industry ensured its continued use.[12] During the Napoleonic wars this number dropped to 9.7 percent. However, this was due to complete British sea control and Napoleon’s interest in a closed, continental system wherein Europe stood alone and isolated Britain from its major trading partners.[13] The persistence of privateering indicates its potential profitability and utility, even when a state chose to turn to the land.

The end of the 19th century saw the end of privateering as an institution due to the efforts of the British Empire. The Declaration of Paris in 1856 saw first the British, and then almost all other Western powers—except for Spain, the United States, and Mexico—abandon the practice and vow not to harbor privateers or their prizes. It is worth noting that this abolition of privateering followed a period of prolonged peace and only was adopted as a platform by the British during the Crimean war. The abolition of privateering was part of a greater effort to prevent U.S. sailors from taking Russian Letters of Marque and cruising against Britain’s otherwise unchallenged merchant trade.[14] However, disposing of this method of fleet augmentation would force navies to adapt and eventually turn towards the auxiliary cruiser.

20th Century: Filling the Gaps with Auxiliaries and Emerging Lethality

Novel technology fundamentally changed the tactical nature of naval warfare. Beginning with the Hunley’s sinking of the USS Housatonic (AO-35), warships could be destroyed by an enemy they could neither locate nor defend against: the submarine. Perhaps the most dramatic display of the surface blockader’s vulnerability came in the opening months of World War I with the sinking of the “Live Bait Squadron.” The squadron, consisting of the older heavy cruisers HMS Aboukir, Cressy, and Houge, was attempting to conserve coal to extend its on station time. The German submarine U-9 closed and annihilated the entire squadron within 90 minutes.[15] Their high fuel consumption rate and relatively small bunkers limited their speed and subsequently left them vulnerable.

The emergence of steam as the primary mode of propulsion had numerous effects. It limited the range and endurance of warships as shipwrights sought to balance speed, armor, and endurance. No longer could vessels remain on station indefinitely, they either needed to engage in highly vulnerable re-coaling at sea or return to port. So too were cruisers and commerce raiders limited, no longer could a ship take to the seas and remain beyond the reach of land and enemy ships for months or years.

World War I clearly demonstrates the superiority of a capture based blockade and the utility of auxiliary naval units. The British blockade enforcement squadron, the 10th Cruiser Squadron, transitioned to armed auxiliaries in November of 1915. The increased endurance and crew size of these vessels made them extremely effective.[16] During the war the 10th Cruiser Squadron intercepted 12,799 ships, of which 3,955 were detained. Only 642 ships successfully evaded the blockading squadron, a successful interdiction rate of 95 percent.[17] This strategic blockade was so effective that it resulted in an 89 percent reduction in German maritime income.[18] Eventually, the entry of the United States resulted in the end of the 10th Cruiser Squadron’s blockade.[19] It no longer necessary once the main neutral bent on continued trade had entered the war.

A similar blockade failed to materialize during World War II because of U.S. outrage, the lack of a major trading neutrals, and the effective allied control of supplies bound for Spain. At the start of the war, Franco’s Spain remained neutral and received regular merchant traffic from the Americas. While there was a concerted effort to smuggle small, compact goods to Europe, the British, and later the Americans, instituted a practice called NAVICERT wherein neutral shipping that did not submit to inspection and approval prior to shipment was subject to seizure. This was accomplished through the cooperation of the neutral South and Central American republics.[20]

During World War I German naval strategy leaned heavily on naval auxiliaries. Numerous German liners and cargo ships were built for wartime conversion to commerce raiding and there was a standing plan to utilize German overseas basing and converted merchants to wage a traditional campaign of guerre de course.[21] Had Germany’s overseas bases not fallen so rapidly and the German raiders not swept up so quickly the strategy may have worked and prevented the eventual slide into unrestricted submarine warfare.

Following the failure of their surface cruisers the Germans turned to their submarines to assault British trade. While they could slip past the British blockaders, they were fragile platforms with small crews. They could not spare the men to man a prize and generally sank their captures after evacuating the civilian merchants. Technically this was legal because under existing prize law a prize that threatened the safety of the capturing vessel could be destroyed. As Entente merchants began resisting capture German submarines simply started sinking them, and even neutral shipping possibly carrying “contraband,” without warning. The practice became known as “unrestricted submarine warfare” came to the fore. However, while resulting in the destruction of a large quantity of shipping, unrestricted submarine warfare eventually drew the United States into the war and further deepened Germany’s strategic problems.[22]

The United States waged the only successful campaign of unrestricted submarine warfare. The success of this campaign occurred because Japan was not significantly industrialized, placed little emphasis on antisubmarine warfare, and did not possess a strong neutral trading partner. The main factors that hampered the German efforts and ultimately made them counterproductive simply did not exist, and Japan’s industrial base was not strong enough to compensate for destroyed shipping.

Stumbling Blocks for the Modern Warship

As demonstrated by the annihilation of the Live Bait Squadron in World War I, modern warships are ill-suited for the conduct of prolonged blockade operations. Their cramped living quarters and the demands of combat limit the number of crew that can be spared to man prizes and space that can be used to house captured merchant mariners. The slow speeds required of boarding operations and requirements of VBSS support dictate that an extremely expensive asset remain idle in potential submarine threat areas. Furthermore, the engineering lineup required to maintain countersubmarine maneuvers limit on-station time by consuming fuel at a high rate.

Unlike the total war environment of World War II, the U.S. military now operates in a traditional, multipolar political environment and the deliberate slaughter of civilians is considered a war crime. Compunctions about the deliberate targeting of civilians began to slip during World War I and were dissolved entirely during World War II. However, this was due to the total mobilization of populations and the sheer scale of warfare. In the context of limited war, any theoretical blockade must account for civilian lives and possible environmental damage or risk provoking a neutral or destabilizing domestic opinion.

The sinking of a supertanker carrying crude to China through the straights of Singapore would outrage the vessel’s owners and every partner country in the region. The environmental impact would be horrendous and prompt international outcry. Such an action could turn regional allies towards the Chinese or away from the United States. If the ship or its crew was neutral, say Russian or Indian, the sinking could even draw another power into the conflict on the side of the Chinese. Conversely, the boarding and capture of said supertanker would provide the United States with an asset, deprive the Chinese of much needed fuel, and dissuade China’s trading partners. Thus isolated, China’s economy could slip until the Chinese state decided to sue for peace.

Building a Modern Blockade and Supplementary Surface Forces

Naval augmentation remains a strategic necessity. While the nations of Europe have distanced themselves from the practice of privateering it remains enshrined in Article 1 Section 8 of the U.S. Constitution and most of the states existing in current areas of interest were not in existence as independent entities in 1856. Asia, the Middle East, and Africa all contain relatively new threats and states that are adjacent to major, strategic trade routes. Privateers operating in a traditional fashion and bringing prizes into friendly ports would, theoretically, be legal.

So too can prize law be revived and modified. Union naval personnel benefited handsomely from prizes captured during the Civil War and in the United States the practice of U.S. personnel receiving prize money only died during the Spanish American War. Prize taking is still technically legal during wartime but in the United States and the United Kingdom, the nation is now the sole beneficiary.[23] Prize money would provide privateers or auxiliary cruisers with potent mission accomplishment motivations. It also would incentivize further private investment stimulating technological innovation and further platform investment.

In the modern context, irregular naval units would function in a manner like the Royal Navy auxiliary cruisers of World War I or even the German surface raiders of WWII. Containerships could be built to certain specifications to allow for wartime conversion to privateers or naval auxiliaries in exchange for tax credits and other incentives. Alternatively, the United States could activate the ships of the National Defense Reserve Fleet and modify these platforms to conduct blockade duties.[24] During wartime, these relatively inexpensive platforms would execute interdiction operations in conjunction with small boats while regular warships conducted combat operations.

If a privateering model is adopted interdiction operations could become widespread and effective extremely quickly. Privateers or naval auxiliaries would operate as hubs for prize crews, prisoners, small boat refueling and resupply, drone surveillance, and C2. Configurable containers could allow these ships to carry small helicopters or drones to facilitate boardings. Allowing these ships to operate on prize money they would be of little cost to the U.S. government while incentivizing crews to be aggressive and effective. These vessels could even operate on the same logic as privateers but simply be called naval auxiliaries.[25] The risk of a devolution to petty piracy at the end of a conflict is a far cry from what it was during the 16th and 17th centuries as regular states have asserted their authority over most of the globe.

British blockades of the European mainland operated a two-tiered principal. Scouting units—cruisers and destroyers—would remain close to the French or German coastline.[26] These units acted as pickets which would allow larger ships to maintain a long standoff. This essential plan could be lifted directly into a modern blockade schema with great effect. The size of the platforms would have to change but the essential dynamic would remain the same: small boats/ships in close and large warships at range providing defense and tactical support.

In addition, in international chokepoints and straights it may be helpful to simply adopt the tactics of modern pirates but with much more capable platforms. A chokepoint blockade would consist of small boat swarms operating out of costal bases that would move quickly and stealthily to board enemy merchants–by force if necessary. Their proximity to land would minimize the problems of crew detention and could provide a pool of prize crews to carry the vessel in question back into a friendly port. The impetus of prize money, and the nature of investment, would cause the American firms backing these privateers to invest in highly capable platforms and competent sailors. This would lead to innovation in boarding techniques and technology and could cause an upward spiral of efficacy. Licensing these men, or granting them some form of commission, could place them under the Uniform Code of Military Justice and would therefore bind them to the orders of regular naval units. This would allow theater commanders to take direct control or allow them to operate semi-autonomously and in accordance with received intelligence.

Assuming these coastal enclaves are not cleared out, these small boat interdiction squadrons could prove highly effective. Their shallow draft would essentially make them immune to torpedo attacks and their high speed would allow them to outrun most surface combatants. Additionally, assuming maritime superiority outside of the littorals and choke points, they would probably benefit from some degree of Aegis based air defense. Theoretically, the only way for a blockaded state to rid themselves of these raiders would be to invade and clear out their bases. Admittedly, this relies on the acquiescence of friendly, strategically important states but it is a viable, and potentially extremely effective option.

Conclusion

Admittedly, Corbett takes a dim view of privateering as a practice. While advocating for a policy of “commerce prevention,” he denounces privateering as inhumane.[27] His strategic advocacy is commendable but his rejection of potential tool of warfare as “primitive and unscientific” denies privateering its past utility.[28] Given the increasing prevalence of communication technology and the current strength of the rule of law there is no reason that an organized privateering campaign cannot be effective. Either way rapid augmentation of regular naval forces with irregular forces and civilian craft has again come to the fore of naval strategy. Chinese maritime militias and the Iranian Revolutionary Guard Corps Navy’s small boats represent a return to irregular naval units. Neglecting the potential utility of naval auxiliaries or privateers grants potential opponents a potential operational edge that the United States navy would be unable to match.

The continued importance of maritime trade to national economies dictates that naval strategists determine effective ways to strip opponents of their access to global markets. As the whole sale destruction of shipping, the environment, and civilian lives is not acceptable it falls to the surface force to interdict and deter enemy shipping as well as tangle with increasingly competent and capable naval foes. This calls for additional ships and the historical model for rapidly expanding navies remains demonstrably viable. Privateers and naval auxiliaries provide the best option for blockade operations. Therefore, the U.S. government should start building contingency plans for eventual operations.

Endnotes

[1] Julian Corbett, Some Principals of Maritime Strategy, (London, 1911), Kindle ed. loc 1021.

[2] John Frayler, “Stories From the Revolution: Privateers in the American Revolution,” National Park Service, last updated 4 December 2008, Accessed 29 June 2017, https://www.nps.gov/revwar/about_the_revolution/privateers.html.

[3] Arthur Herman, To Rule the Waves; How the British Navy Shaped the Modern World, (New York, HarperCollins Publishers 2005), 50-52.

[4] Grover Clark, “The English Practice with Regard to Reprisals by Private Persons.” The American Journal of International Law 27, no. 4 (1933): 694-723. doi:10.2307/2190115, 694.

[5] Robert Ritchie “Government measures against Piracy and Privateering in the Atlantic area,” Pirates and Privateers; New Perspectives on the War on Trade in the Eighteenth and Nineteenth Centuries, ed. David J. Starkey, E.S. van Eyck Van Helslinga and J.A. De Moor (Devon, University of Exeter press 1997), 18.

[6] Herman, To Rule the Waves, 51.

[7] Ibid., 51-53, 99.

[8] Philip Gosse, The History of Piracy, 114-116.

[9] Herman, To Rule the Waves, 227-228.

[10] Ibid., 227-229.

[11] David Starkey, “A Restless Spirit; British Privateering Enterprise; 1739-1815,” in Pirates and Privateers; New Perspectives on the War on Trade in the Eighteenth and Nineteenth Centuries, ed. David J. Starkey, E.S. van Eyck Van Helslinga and J.A. De Moor (Devon, University of Exeter press 1997).

[12] Ibid., 137.

[13] Ibid., 130-131.

[14] Ritchie, “Government measures against Piracy and Privateering in the Atlantic area,” 22-24.

[15] Richard Dunley, “The Live Bait Squadron,” The National Archive, 22 September 2014, http://blog.nationalarchives.gov.uk/blog/live-bait-squadron/

[16] Paul Halpern, A Naval History of World War I, (Annapolis, Naval Institute Press 1994), 47-49.

[17] Ibid., 50.

[18] Louis Guichard, The Naval Blockade; 1914-1918 Trans. Christopher Turner, (New York, D. Appleton and Company 1930), 128.

[19] Halpern, A Naval History of World War 1, 50.

[20] W.N. Medlicott, The Economic Blockade, (London, H.M. Stationary Office 1952), 2-3

[21] Halpern, A Naval History of World War I, 66-67.

[22] Paul Halpern 291-292.

[23] Donald Petrie, The Prize Game; Lawful Looting on the High Seas in the Days of Fighting Sail, 141-142.

[24] “National Defense Reserve Fleet,” US Department of Transportation; Maritime Administration, accessed 29 June 2017, https://www.marad.dot.gov/ships-and-shipping/strategic-sealift/office-of-ship-operations/national-defense-reserve-fleet-ndrf/.

[25] The legal framework for rapid fleet expansion and the creation of viable naval auxiliaries designed for commerce interdiction exists in a number of forms. The Letter of Marque is enshrined in the US constitution in Article 1 section 8. However, the use of contractors in a potentially naval role is also found in the Maritime Security Act of 2003 which states that vessels may be authorized as part of a “Maritime Security Fleet” if “determined by the Secretary of Defense to be suitable for use by the United States for national defense or military purposes in time of war or national Emergency.” “National Defense Authorization Act 2004,” Government Publishing Office, accessed 29 June 2017, https://www.gpo.gov/fdsys/pkg/PLAW-108publ136/html/PLAW-108publ136.htm

[26] Herman, To Rule the Waves, 284-287.

[27] Corbett, Some Principals of Maritime Strategy, loc 1031.

[28] Ibid., loc 1044. Starkey, “A Restless Spirit,” 131-137.

Author’s note: I would like to thank Professor Wayne Hughes, Professor Joyce Sampson, Captain Chuck Good, Lieutenant Dan Justice, Lieutenant Dave Bundy, and Sasan Mousavi for their assistance and guidance. Their help was invaluable.