The past two centuries produced three key technologies that radically altered the nature of naval warfare: steam power, the submarine, and the airplane. Naval technologies with important, but lesser effects on the nature of naval warfare include missile technology, nuclear weapons, and iron/steel armor. Of these, the submarine and nuclear weapons seem to have played the largest role in radically changing how the world’s navies viewed naval strategy. We can see these technologies at play most clearly in the naval arms races of the Nineteenth century and the major wars of the Twentieth century.
The development of steam power was the earliest of these technologies because it showed that the Royal Navy might be unable to defend England from invasion across the English Channel, and would also be unable to conduct close blockades of ports on the continent, as it had done during the Napoleonic Wars. Eric grove argues that because steam ships could navigate without reference to the wind, they could take routes and land at points that the Royal Navy would not be able to predict. The Crimean War showed the possibilities of steam-powered vessels (and the deficiencies of British ships) as French ships equipped with high horsepower steam engines easily navigated the passage of the Dardanelles against the wind.
C.I. Hamilton argues that the steam power and focus on torpedoes by the jeune ecole played a key role in the Anglo-French Naval arms race from the time of the Eastern Crisis of 1839/40 through the 1860s. France also developed steam-powered torpedo boats to prevent the Royal Navy from using a close blockade against French ports in the case of war. This was part of a French attempt to change the nature of naval war away from the emphasis on large fleet actions in the face of a larger British fleet. Steam technology led France to develop doctrines of ramming, commerce raids, amphibious landings, and coastal defense as opposed to large clashes at sea.
The development of the submarine provides one of the most persuasive arguments against the Mahanian obsessions of the British, German, and Japanese navies. Even the primitive gasoline-powered submarines of World War I made the guerre de course a serious naval threat. The stealthy nature of the submarine allowed them to slip past the British blockade of Germany in the North Sea and sink sufficient merchant traffic that Germany was almost able to force Great Britain out of the war. To counter the submarine threat, Great Britain and the United States had to abandon their hopes for decisive clashes of the battle fleets, and their preference for offensively minded operations. Lack of sufficient numbers of escorts and a preference to use destroyers to seek out and destroy submarines kept Great Britain from using convoys to defeat submarines before the United States entered the war in 1917. Before that point, Great Britain attempted to divide the Atlantic into sectors patrolled by warships, but the large sweep of ocean and lack of effective detection technology thwarted British schemes.
The United States’ entry allowed a shift of tactics to convoying merchants and troop transports to England and France just in time to keep Great Britain in the war. The convoy system relied on escorts to control only the portion of the ocean that the convoy was in. George Baer argues that rather than following Mahanian doctrine and focusing on sinking the submarines, convoy escorts merely sought to drive them off. At the outset of the war, the United States Navy did not understand the true nature of the submarine threat, despite the fact that a fleet of only forty submarines was on the verge of starving Great Britain out of the war. Sinking a submarine was merely a bonus for the effort when it occurred. The goal in this first battle of the Atlantic was to gain local, defensive sea control. The convoy system defeated the U-boats – only 400 of 95,000-convoyed ships were lost. In addition, the United States Navy transported almost half of the 1.7 million U.S. troops sent to the European theatre. Using destroyers, cruisers, and battleships as escorts, the USN didn’t lose any of the troopships to enemy action.
Submarines were also critical in the Mediterranean during World War I. Paul Halpern argues that once Austria-Hungary and Germany began using submarines in the Mediterranean in 1916-17 to attack merchants between England and its overseas empire, Allied ships were put on the defensive. British dominance in antisubmarine warfare meant that they had to lead the fight against submarines, while the French Navy focused on the surface war. As in the North Atlantic, Halpern contends, German and Austrian submarines were successful in sinking hundreds of thousands of tons of merchant shipping until Great Britain instituted convoys in 1917. Once again, Great Britain had to learn the hard lesson that offensive campaigns against submarines were not effective, as shown by the failure of their bombardment of Otranto to have any effect on the submarine threat. German submarines were so effective, that German Admiral von Holtsendorf believed that the war would end by the autumn of 1917. As in the North Atlantic, Jellicoe resisted convoys because he viewed them as inherently defensive uses of ships, but finally succumbed to pressure and turned away from offensive operations in favor of convoys.
This battle of the Atlantic was repeated during World War II when Germany did not possess a significant battle fleet for Great Britain and the United States to fight in the North Atlantic. Once again, Great Britain and the United States faced a serious submarine threat, this time with improved technology on both sides – the Allies relied on active sonar, radar, and radio direction finding to locate submarines while German submarines began to use diesel engines giving them greater range and speed using equipment to detect radar, and relying on Wolfpack tactics to avoid detection by sonar. Allied use of radar starting in 1943, along with depth charges, and magnetic anomaly detectors provided them the technological edge to defeat the Nazi wolfpacks.
During World War II, naval aviation played an important role in naval battles after dive-bombers that could carry significant bomb loads were developed. However, despite extending the range at which fleets engaged, and changing the primary weapons from naval artillery to bombs, the effect of naval aviation was primarily to change which capital ships were most able to attack enemy on land or sea. The next major technological changes to alter the nature of naval warfare were ballistic missiles and nuclear weapons.
As the Cold War started, naval strategy shifted due to the focus on atomic weapons and strategic bombing. The Soviet Union posed no threat the American control of the sea until after it adapted submarine technology captured from Nazi Germany. Jakob Grygiel argues that the lack of a naval threat and focus on strategic bombing forced the United States Navy to shift its focus from a doctrine focused on attacking enemy fleets, to maintaining sea lines of communication to Europe open to allow the reinforcement of Europe in case of Soviet invasion, developing long-range strike capability against the Soviet Union, and defending the periphery as part of George Kennan’s strategy of containment. This plan required the Navy to keep the Soviet Union confined to the Black and North Seas so that the Middle East and England could be used as beachheads for the liberation of Europe. When NATO strategy changed in 1949 to the defense of Europe, the USN changed its objectives again to attacking the Soviet Navy o keep the SLOC open.
Through the 1960s and 1970s, American naval strategy remained essentially defensive – protecting the sea-lanes, keep Soviet missile submarines away from the U.S coasts, and escort relief forces to Europe. John Hattendorf argues that despite the nuclear threat, during the 1970s Admiral Holloway, Chief of Naval Operations during the early 1970s began to emphasize carrier battle groups as a policy alternative to continual escalation of nuclear threats. Holloway sought to deemphasize technological change by showing the connection between the Navy and foreign policy and using the navy to push the Soviet Navy away from the SLOC. Forward deployments would allow the USN to contain crises. These changes followed the Navy’s new emphasis on attacking the shore from land using conventional and nuclear-armed aircraft in a manner emulating Julian Corbett’s doctrine rather than a Mahanian focus on the enemy battle fleets.