Old Lessons for New Maritime Statecraft


From the onset of the Cold War through the 1980s, then from the “unipolar moment” through the long wars of the 21st century, the U.S. Navy operated with the same congressionally mandated mission. Despite major changes in the world, Congress did not see fit to adjust the Navy’s formal mission as defined in Title 10 of the U.S. Code in 1956. This was a mission focused solely on fighting or being ready to fight wars, and this focus profoundly shaped the naval services. 

But now, amidst a much-discussed shift toward great power competition, the Navy is finally receiving a new mission. In December 2022, Congress passed and President Joseph Biden signed the James Inhofe National Defense Authorization Act. Section 913 of the act fundamentally adjusted the responsibilities of the U.S. Navy. Not only is the service responsible for fighting the nation’s wars on and from the sea, but it also is now responsible for “the peacetime promotion of the national security interests and prosperity of the United States.” This creates the opportunity for what Secretary of the Navy Carlos Del Toro has called a “new maritime statecraft.” But this will only be successful if the Navy engages with an open and deep discussion of the operations, doctrines, fleet architecture, and strategies needed to execute its responsibilities in both war and peace.

The Many Missions of the Interwar Navy

Despite the significance of the recent change and the dramatic increase in the Navy’s global responsibilities that it suggests, there has been little discussion of it either from official Navy sources or in the national security community more widely. Perhaps one reason for this is that they are still trying to understand it. With this in mind, it is valuable to turn to the history of the formal mission, or missions, of the U.S. Navy, particularly, the years between World War I and World War II when the U.S. Navy executed peacetime missions. 



In 1956, Congress passed and President Dwight Eisenhower signed the law containing the missions of the American military services in Title 10 of the U.S. Code. Previously, though, the tasks to be performed by those armed services had largely been left up to the executive branch. In the interwar years, it became common for the secretary of the Navy to define the missions of the Navy and Marine Corps themselves and elucidate those missions in their annual report that was submitted to Congress via the president. 

In 1920, as demobilization plans were under way after World War I, Secretary of the Navy Josephus Daniels wrote that “the American Navy has from its inception been a force for peace and righteousness.” Looking to the aftermath of the war, Daniels saw the Navy as a key diplomatic and economic actor “in the front rank of the champions of justice and healing.”

Acting on this vision, the U.S. Navy redeployed and remained engaged across the world. In the eastern Mediterranean and Black Sea, American naval forces worked with the U.S. Food Administration and nongovernmental organizations like the Red Cross to deliver food aid in famine-stricken parts of Europe. Coordinating warehouses, port facilities, and security for both U.S. government and nongovernmental aid, the same forces helped evacuate civilians as Soviet forces invaded south into Ukraine during the Russian Revolution They also conducted humanitarian operations to protect civilians during the rise of the Turkish Republic. In the Pacific, the U.S. Navy conducted maritime security patrols and protected American citizens and business interests in the region. As civil war engulfed China and warlords threatened the safety of Americans and Chinese civilians, the U.S. Navy began protecting river traffic on the Yangtze. 

Regardless of the political party in control of the White House, these kinds of peacetime deployments became the norm throughout the two decades between the world wars. When the former Republican Congressman Edwin Denby was appointed to be Secretary of the Navy by President Warren Harding, he wrote, “[t]he Navy’s functions in time of peace are not confined solely to the activities connected with its primary mission — preparation and readiness to act in the defense of the Nation.” In 1922, Denby began to put together an explicit naval policy and set of missions for the fleet. At the end of the year, he reported to the president and Congress that the Navy Department had formally adopted a “fundamental” naval policy and that the “Navy of the United States should be maintained in sufficient strength to support its policies and its commerce, and to guard its continental and overseas possessions.” This remained the core of American naval policy through the Calvin Coolidge administration. 

Denby was forced to resign during the Teapot Dome scandal, but as his successor Curtis Wilbur approached the end of his time as secretary, he introduced a formal list of missions of the fleet. Wilbur’s list began with the “maintenance of battle efficiency,” or the readiness of the fleet for war. However, that was followed by “protection of American interests in disturbed areas, cultivation of friendly relations with foreign peoples,” and finally “close cooperation between the Department State and the Navy” in order to effect the peacetime missions. There was an interagency element to these missions, and it was integrated to provide deterrence. Adams’ list was almost exactly the same, adjusting only the phrasing of the first missions by adding the euphemism “in case of national emergency,” reinforcing the core belief in a balance between the readiness for war and peacetime responsibilities across presidential administrations.

For the remainder of the Hoover administration and into the Franklin D. Roosevelt administration, the Navy’s mission statements continued to emphasize peacetime responsibilities that sometimes varied in verbiage but rarely in intent. Providing aid and assistance to countries in need joined the list in 1930, the precursor to what late 20th- and early 21st-century naval policymakers and strategists would call humanitarian assistance and disaster relief. In 1933, when Claude Swanson took the helm of the department, he charged the Navy to “cooperate fully with other departments of the Federal Government and with the States,” thereby recognizing that American maritime power was a whole-of-government concern. Swanson returned to an idea that had been presented at the start of the Harding administration: the creation of a formal “Naval Policy” of the United States. In doing so, he adopted language directly from Secretary Denby’s statement a decade earlier, emphasizing the role of supporting the country’s “national policies and commerce.” 

The Roosevelt administration policy eventually became more specific, enumerating a list of 14 tasks. The first four elements or missions focused on the creation of a fleet with “maximum battle strength” and a Marine Corps ready “to provide expeditionary forces in immediate readiness,” with “war efficiency the object of all development and training.” These tasks, however, were followed by 10 additional missions that focused on the peacetime responsibilities of the Department of the Navy. These included the protection of American lives and property overseas, the development of American commerce, deployments to “cultivate friendly international relations,” and extension of the task “to encourage civil industries and activities useful in war.” In the years from the start of Roosevelt’s presidency through the outbreak of war in Europe in 1939, Swanson’s annual messages to the president and Congress continued to highlight these 14 tasks, equally balancing them between the wartime and peacetime responsibilities and highlighting for America’s elected representatives that naval forces had many important missions. 

Of course, mission statements devised by military staffs do not always match up with the execution or the operations of their forces. But my research confirms that between the World Wars, maritime statecraft was central to how the Navy operated and what the nation expected of it. Reading the secretary’s annual reports from 1920 to 1939 alongside the operational reports of the chief of naval operations and the commandant of the Marine Corps for those years reveals that the Navy and Marine Corps were enormously busy conducting operations around the globe. They protected American citizens and American commerce from the Pacific to the Mediterranean to the waters of Latin America. They cooperated with American business interests overseas and conducted naval diplomacy and collaborated with the State Department and nongovernmental organizations. They helped defuse rebellions, organized elections, and conducted humanitarian relief operations after natural disasters across the world — while engaging in some considerably uglier behavior as well.

Readiness for War and a Mission for Peace

The conventional narrative of the U.S. Navy and Marine Corps in the interwar years is the story of the development of the fighting doctrines and technologies that would be used to help defeat the Axis powers in the coming war. This narrative is valuable, and talented historians have focused on it and given us important insights. This narrative remains a popular one in naval professional writing in the 21st century as well. 

By returning to the Navy Department’s annual messages and operational reports of the interwar years, we can see that the narrative of doctrine and technology is accurate but incomplete. The Navy and Marine Corps were directly engaged in maritime statecraft and peacetime missions a century ago. As today’s sea services work to implement the mission change ordered by Congress and the president, returning to the years of the Roaring ’20s and 1930s offers a starting point for discussion. 

Under Secretary Swanson, the U.S. Navy was tasked with becoming the world leader in naval technology, ships, and weapons. The Navy also considered the collaboration with industry and the inspection of all naval facilities and material as part of the mission, looking for a brutally honest assessment of the fleet and the support it needed. And the Navy actively tasked itself with “encouraging” civil industries and activities as well as developing plans for industrial mobilization. They also worked to actively improve their “system of progressive education” for the officer corps and sailors. These were important elements in the 1930s, but they remain critical to the debates and discussions over readiness today. Reflecting on these might lead to consideration of the success of the “Get Real, Get Better” program, the “Education for Seapower” effort, and the adoption of foreign naval designs and weapons.

The Navy and Marine Corps’ activities in the wider world were also fundamental to how the interwar services saw their missions. The protection of American lives and property overseas seems an obvious starting point then, as it is now. Additionally, the Navy looked to support American interests in global competition, from freedom of navigation to other efforts to support American commerce. Visiting foreign ports, making worldwide cruises, and developing international relationships were all part of a naval diplomacy and a robust global presence. Moreover, to accomplish these tasks effectively, the Department of the Navy called for full cooperation “with other departments of the Government,” making maritime statecraft a whole-of-government issue long before the term was coined. 

As Washington enters an era of great power competition, it can gain valuable insights from the Navy’s interwar success in conducting peacetime operations while still preparing for war. This means thinking about, talking about, actively developing new doctrines for, and understanding how to plan the complex needs of the peacetime missions of the Navy and Marine Corps. 



Captain B.J. Armstrong, PhD, is currently serving as Admiral Jay Johnson Professor of Leadership and Ethics and associate professor of war studies and naval history in the history department at the U.S. Naval Academy. His new books Naval Presence and the Interwar U.S. Navy and Marine Corps: Forward Deployment, Crisis Response, and the Tyranny of History, and 21st-Century Mahan, Revised and Expanded: Sound Military Conclusions for the Modern Era were published this past summer. Opinions expressed in his article are offered in his personal and academic capacity and do not reflect the positions or policies of the U.S. Naval Academy, the Department of Defense, or any other agency.

Image: United States Navy