The United States once unquestionably ruled the seas—but that is no longer the case. In 1966, the U.S. Navy had 909 active ships protecting American interests at sea. Fifty years later, in 2016, that number had fallen to 275. In 1949, the U.S. accounted for more than 70 percent of the world's naval power; by century's end, that figure stood at about 45 percent.
One might surmise that fewer military ships roaming the seas would make the world safer. However, University of Iowa Professor Sara Mitchell has found that the opposite is true: increasing U.S. sea power would strengthen rules-based international conflict management and help keep the peace among maritime nations.
Mitchell, the F. Wendell Miller Professor of Political Science, articulates this liberal case for increased United States sea power in a recent article in War on the Rocks, an influential foreign policy and national security website. The article’s co-author is Professor Jonathan Caverley of the United States Naval War College.
Mitchell and Caverley analyzed the new tri-Service maritime strategy unveiled by the U.S. in November 2020. The strategy, dubbed “Advantage at Sea,” is designed to utilize the U.S. Navy, Marine Corps, and Coast Guard to prevail in day-to-day competition, crisis, and conflict in maritime issues over the next decade. Among its assertions are the need for an increase in the number of U.S. military ships and a more interventionist approach to maritime military policy.
Because the Trump administration often focused on the political imagery of a powerful military presence at sea, some have reacted to the new strategy with skepticism. However, Mitchell and Caverley note that many of the new maritime strategy’s core elements mesh well with liberal international conflict management.
The authors build upon Mitchell’s ongoing research on the onset and escalation of diplomatic conflicts involving maritime, territorial, river, and identity issues. As co-director of the Issue Correlates of War (ICOW) project, Mitchell has collected data on 270 diplomatic conflicts over maritime areas from 1900 to the present. This includes disagreements about maritime boundaries (for example, a dispute between the United States and Canada over the boundary in the Gulf of Maine), access to marine resources (such as the U.S. vs. Ecuador and Peru regarding tuna fishing), and navigational rights (a dispute between the United Kingdom and Albania involving the Corfu Strait, for instance).
Mitchell’s research shows that the frequency of maritime conflicts in the past century increased significantly as America’s total share of global naval power declined. Many states, such as China, Iran, and Russia, are now making revisionist claims at sea and are investing heavily in naval buildups, increasing the risks for future maritime conflicts with the United States and its allies.
Mitchell’s findings suggest that when naval powers are evenly matched, they more often engage in peaceful negotiations. This phenomenon is illustrated by the U.S. protection of Japanese interests against Chinese claims of sovereignty over the disputed Senkaku/Diaoyu islands in the South China sea. By committing robust sea power to defending Japan’s interests, the U.S. has been able to thwart China’s annexation of the islands. Mitchell’s research concludes that by increasing its naval power to match that of adversarial nations more broadly, America can play an important extended deterrence role in other maritime conflicts around the world.
Another factor in evaluating the tri-Services maritime strategy is the fact that climate change exacerbates the risks of clashes at sea. Rising sea levels will alter states’ baselines for territorial sea and economic exclusive zone (EEZ) claims and reduce access to resource-rich marine areas, setting the stage for future conflicts. Mitchell and her PhD students, Bomi Lee and Cody Schmidt, have shown that greater volatility in annual rainfall levels increases the risks for the use of militarized force to settle diplomatic conflicts involving maritime (or other) issues.
The tri-Services maritime strategy offers a path for alleviating these risks by using a larger and more diverse naval force to manage maritime conflicts and protect shipping lanes.
Mitchell notes that the risk of maritime conflicts is not just among adversarial nations. While democratic countries are peaceful in general, she and University of Iowa political science alumna Kelly Daniels found that pairs of democracies have the highest risks for maritime conflicts (such as those between the U.S. and Canada, United Kingdom and Iceland, and Canada and Denmark). Accordingly, a stronger and more interventionist U.S. maritime fleet is well positioned to manage conflicts among friends and foes alike.
Mitchell discusses her research in more detail in a Sea Control podcast interview with the Center for International Maritime Security (CIMSEC).
The ICOW project has received generous funding from the Department of Defense Minerva Program, the National Science Foundation, and the United States Agency for International Development.