The heralded return of great power competition merits a review of the lessons of the 20th century, which was shaped by great power struggle. As acknowledged in A Design for Maintaining Maritime Superiority Version 2.0, national-security planning is being more explicitly influenced by great power considerations than at any other time since the collapse of the Soviet Union.[1] The crucial lesson of the great power struggles of the 20th century is that while focusing exclusively on the relative technical capabilities of naval forces might be adequate to win a war once entered, it is insufficient to win the peace. To prevent the outbreak of open warfare between great powers, it is imperative to develop and maintain credible international alliances.
Pre-World War I
In its quest to become a world power, the German government at the turn of the 20th century began an ambitious ship-building program with the goal of challenging Britain’s Royal Navy. The British responded in kind; by 1914 the Germans had 17 dreadnoughts (large battleships) and the British had 29.[2] On a relative power basis, the Germans were outmatched by the British at sea. When combined with Russian and French naval forces, as with land forces, the Germans were far outnumbered.
This relative power difference, however, mattered less than the perception by leaders of Germany and Austria-Hungary that the other European great powers would not join forces, or if they did, that they would not be able to coordinate in a way that capitalized on their numerical superiority. France, Britain, and Russia viewed each other with suspicion, and each was hesitant to commit their forces fully in the aid of the others. In Britain, just three weeks prior to the final declaration of war in 1914, three quarters of the cabinet still insisted on staying out of a continental war unless Britain were attacked.[3] The German and Austro-Hungarian alliance assessed it could divide and conquer the other great powers in rapid succession.
The Interwar Years
President Woodrow Wilson explicitly addressed the need for credible, effective international alliances in his Fourteen Points speech presented at the Paris Peace Conference after the war. “A general association of nations must be formed under specific covenants for the purpose of affording mutual guarantees of political independence and territorial integrity to great and small states alike.”[4] This was a departure from the limited alliances that were ineffectual in the lead up to World War I. Rather than continuing the pre-war practice of building complicated networks of mutual defense treaties between major powers, Wilson envisioned an international organization that would act as a venue for de-escalation and, most importantly, as a credible deterrent to any one state’s future aggression.[5]
While the Treaty of Versailles and the League of Nations were intended to make another war between great powers impossible, they failed. Both the impotence of the League and the punitive interwar structure of the peace fueled a resurgent Germany that within two decades embarked on another war predicated on the presumption that it could attack its adversaries piecemeal and win, which it very nearly did.
From a naval standpoint, the interwar period was characterized by a focus on restraining the growth of naval fleets such that the relative strength of the various great power navies was maintained. The Washington Naval Conference of 1921–1922 was the first of a succession of conferences that dealt with these limitations and produced series of commitments among the United States, Britain, Japan, France, and Italy to restrict both the size of capital ships as well as the number of certain types of ship each country could build.[6] The focus on limiting the relative strength of each navy is symptomatic of the flawed thinking that dominated in the interwar period. As was seen in the German calculus leading up to World War I, being at a numerical disadvantage was insufficient to prevent a country from going to war.
The efforts of interwar American naval leaders to prepare for a two-ocean war were instrumental in winning the eventual war. However, focusing on maintaining a balance of relative power by constraining the growth of international navies did not remove Germany’s or Japan’s incentives to go to war, and the absence of a credible and capable international alliance made a successful outcome for both countries in their wars of aggression seem plausible.
Post-World War II
In the aftermath of World War II, President Harry S. Truman and his fellow international leaders were intent on avoiding the mistakes of the interwar era. Advocating for the U.S. Senate’s ratification of the United Nations, he insisted on the urgent need for approval, appealing to the “reality of experience in a world where one generation has failed twice to keep the peace.”[7] The post-war era saw an attempt to formalize and legitimize international relations and norms that, unlike after World War I, was supported by all of the major world powers (although to varying degrees and with much jockeying between them occurring). As the Cold War took root, the countries of Western Europe and North America added the North Atlantic Treaty Organization (NATO) to the international framework, creating a wide-ranging, transparent, and credible military alliance that for 70 years has deterred great power aggression toward its member states.
The post-World War II order is not perfect, but it is an impressive improvement on the failed peace policies of the first half of the 20th century. The combination of the United Nations and NATO changed the calculus of great power aggression so that potential combatants must consider not just how their armed forces compare to their primary rival, but how their armed forces compare to the combined strength of the armies and navies of much of the globe. NATO’s effectiveness has been the credibility of its defense commitments between member states, seen in the frequent cooperation and coordination of their militaries. The strength of the alliance makes a policy of dividing and conquering, as pursued by Germany in both World Wars, extremely unlikely to succeed.
Lessons for Maintaining Maritime Superiority
The 20th century demonstrates that a focus exclusively on building one country’s naval strength will not preserve the peace. As has been demonstrated repeatedly, in the absence of credible international organizations and alliances, aggressors can and will attack countries one at a time, even if the one-on-one match-up is not clearly in their favor. The U.S. Navy has been at the forefront of the development of these alliances. The Navy has shifted from an interwar focus on being able to win the next war and today has added deterring the next war to its primary goals. This starts with building the capabilities necessary to fight and win future wars, but cannot stop there. Focusing exclusively on technical capabilities yields an arms race that, by itself, will not reduce the likelihood of war and may even increase it. Technological growth and capability enhancement must be coupled with building, maintaining, and strengthening international treaty organizations.
The great naval strategist Alfred Thayer Mahan assesses the fount of naval power to spring from geography, demography, and public policy.[8] The right combination of these allow productive countries to build commercial shipping infrastructure that lays a sturdy foundation for a strong navy. Mahan combines this with networks of colonies to promote power projection. This should be modified for 21st-century application to replace colonies with strong international partnerships, which the post-World War II era has shown to be a more sustainable and just means to allow power projection around the globe.
In his recent book Sea Power, Admiral James Stavridis acknowledges the continuing relevance of Mahan’s work to the present day, modifying the colonial pillar of power to “a strong system of alliances and partnerships around the world.”[9] He advocates using the Navy to strengthen ties globally, consistent with Mahan’s visions of the Navy as an instrument for projecting strength in both peace and war.
The Risk of Re-Learning Past Lessons
In his seminal work on international politics, John J. Mearsheimer offers a sobering assessment of the likely outcomes of realpolitik great power struggles in his aptly titled The Tragedy of Great Power Politics. He describes an inescapable cycle of conflict as states compete with each other for relative power to increase their probability of survival.
Mahan, Stavridis, Mearsheimer, and others share an assessment of the ocean as a key source of security. Mearsheimer describes “the stopping power of water” as being an invaluable aid in securing a nation’s borders, and Stavridis describes the Atlantic and Pacific as “massive guardians” of the United States.[10] Mahan explores the implications of separation of great powers by large bodies of water. Mearsheimer attributes the isolation of the United States by the Atlantic and Pacific oceans as a key reason why the United States has emerged as the only “regional hegemon” of modern times.[11]
The interwar naval policies offer a good example of the risks of viewing the world purely through Mearsheimer’s lens of relative power. The victors of World War I sought security in the form of limiting the capabilities of major powers by constraining the size of both ships and fleets. By focusing on constraining the capabilities of great powers, they neglected to build durable, credible, and capable alliances, allowing Germany and Japan to rise rapidly and exploit the lack of international unity which seemed so close at the end of World War I. This allowed Japan to wage war in Southeast Asia for nearly a decade before the United States was involuntarily pulled into the war and for the Germans to briefly conquer nearly all of Europe.
The peace failed because it focused too narrowly on constraining capabilities in an ill-fated attempt to preserve relative power in favor of the victors. Post-war leaders failed to act on the powerful vision exhorted by President Wilson to make “wars of aggression . . . forever impossible” through the creation of a strong force for international collaboration and cooperation in the form of the League of Nations.[12] The failed naval policies of the interwar years suffered from the same shortcomings of the Treaty of Versailles, namely an inordinate obsession with constraining military capabilities without doing anything substantial to improve the international political incentives which led to World War I. In the end, the rise of Germany and Japan in the interwar years shows the futility of focusing naval policies exclusively on relative capabilities. These policies failed to prevent these countries from achieving the capabilities the policies targeted because they were not coupled with strong international treaty organizations that could be relied upon to check the aggression of pariah states.
The creation of NATO and the United Nations from the ashes of World War II show that the lessons of the failed interwar peace were understood by post-World War II leaders. The biggest difference between the interwar and post-World War II eras is the emergence of a credible and capable international treaty alliance in the form of NATO and the growth of international organizations that contribute to de-escalating conflict and enforcing international norms that make aggression more costly. The continuation of these institutions is not ensured.
Mearsheimer’s view of the hopeless nature of great power conflict is supported by thousands of years of human behavior. The success of the recent peace brings risks of its own. As generations grow up without the first-hand experience of great power war, they risk making the same cognitive mistakes their predecessors in the first half of the 20th century did. We must avoid the risk of falling into the traps of the interwar years and fight to use the mistakes of the past to step off the carousel of war.
Endnotes
[1] Admiral John M. Richardson, USN, “A Design for Maintaining Maritime Superiority Version 2.0” (Washington, DC: 2018) www.navy.mil/navydata/people/cno/Richardson/Resource/Design_2.0.pdf.
[2] Richard J. Evans, The Pursuit of Power: Europe 1815-1914 (New York: Penguin Books, 2016), 701.
[3] Evans, 710.
[4] Margaret MacMillan, Paris 1919 (New York: Random House, 2001), 496.
[5] MacMillan, 87.
[6] Stephen Roskill, Naval Policy Between Wars. Volume I: The Period of Anglo-American Antagonism 1919–1929 (South Yorkshire: Seaforth Publishing, 1968), Kindle Chapter 8 locations 7589-7733.
[7] David McCullough, Truman (New York: Simon & Schuster, 1992), 402.
[8] Mahan, 18.
[9] Admiral James Stavridis, USN, Sea Power: The History and Geopolitics of the World’s Oceans (New York: Penguin Books, 2017), 316.
[10]Mearsheimer, 41; and Stavridis, 330.
[11] Stavridis, 330.
[12] Woodrow Wilson, “Address to the Senate on the Versailles Peace Treaty,” The American Presidency Project, www.presidency.ucsb.edu/node/310230.
