Shields of the Republic: The Triumph and Peril of America’s Alliances. Mira Rapp-Hooper. Cambridge, Massachusetts: Harvard University Press, 2020.

The election of 2016 renewed debate around long-standing frustrations with allied burden sharing and defense commitments, drawing into question the value of U.S. allies, as well as the global role of the United States. What was missing in 2016 was a cogent case for the future of U.S. alliances. Dr. Mira Rapp-Hooper, the Stephen A. Schwarzman Senior Fellow of Asia Studies at the Council on Foreign Relations, wades into the debate with Shields of the Republic, a clear defense of U.S. alliance logics that not only reminds readers what U.S. alliances have accomplished, but largely dispels the myths of their burdensome costs and entangling politics. Perhaps more importantly, she also provides a fresh look at what is required to re-forge these shields and ensure their benefits endure.

Shields of the Republic is a loosely chronological voyage through America’s evolving alliance logics from the nation’s inception to our present. Early chapters examine U.S. war-time alliances, post-revolutionary war skepticism, and the sea-change of the post-WWII era in which the U.S. implemented a novel system of peace-time alliance structures in Europe and Asia to counter the USSR—a strategy without precedent. Later chapters examine the costs and benefits of the U.S. alliance-based strategy in the Cold War before turning to the reemergence of competition from China and Russia and the challenge of reforming U.S. alliances for the 21st-century. It’s an expansive analysis and stands apart from existing scholarship on U.S. alliances that tends to focus on discrete historical accounts or myopic defenses of alliance accomplishments. This expanded scope is welcome and has the advantage of putting the totality of U.S. alliances of the last 70 years in context and allowing for a remarkably thorough and critical exploration of their contemporary strategic purposes and perils.

Shields of the Republic hits the wave tops of alliance logics in Europe and East Asia with speed and precision. This is only possible because of the broad range of history, international relations theory, and policy analysis by which the narrative is buttressed. Readers should note however, this is a study of formal alliances codified in mutual defense treaties. NATO and East Asian alliances come in for close scrutiny, while close non-treaty allies such as Israel or regional partners such as Saudi Arabia, are omitted to better focus on formal alliance structures.

At its heart, Shields of the Republic is crafted on the foundations of the 1943 book, U.S. Foreign Policy: Shield of the Republic by Walter Lippman.[1] Lippman articulates a foreign policy in which a country’s international objectives align with its domestic capacity to support them both financially and politically. A nation becomes insolvent when its international commitments do not align with its domestic resources. Rapp-Hooper persuasively argues current U.S. alliance commitments are nearing insolvency because of the political costs of alliances. U.S. policymakers and strategists have not fully reconceived the role alliances should play in twenty-first century national security strategy.

As a result, Rapp-Hooper observes that the bipartisan political narrative and the answer to the question of why U.S. alliances should endure became obscured. Recent Pew surveys on support for NATO demonstrate the growing divergence between Republicans and Democrats on NATO. Prior to 2017, Republicans and Democrats held largely consistent and favorable views of NATO. That has steadily evolved, with Democrats now more likely to support NATO than Republicans, though views of NATO have declined overall among supporters of both parties since 2018. In 2019, 61% of Democrats had a positive view of the alliance, compared with 45% of Republicans.[2]

The recent bifurcation on views over U.S. alliance structures centers on the most interesting, and perhaps most politically vexing element of Shields of the Republic, the long running debate in U.S. foreign policy about alliance burden sharing and the fear of allied entanglement, abandonment, or entrapment. Rapp-Hooper does excellent work examining the political and economic costs and benefits of Cold War-era and contemporary alliances despite the difficulty assessing the benefits and value of crises and wars that did not happen. Some will undoubtedly take issue with the use of counterfactual exploration here, but the case analysis is illustrative and convincing.

The decision to withdraw some U.S. troops from Germany is just the latest lightning rod in the debate over modern U.S. alliance costs. Despite Secretary of Defense Esper’s argument to the contrary, the move is likely viewed by allies as capricious.[3] This effort also mirrors the same public arm-twisting of allies in the Pacific.[4] Of course, NATO allies already agreed in 2014 to meet the goal of spending 2% of GDP on defense by 2024, and allies in Europe and the Pacific heavily subsidize the U.S. military footprint. Though unlikely to meet their goals by 2024, there is evidence that NATO allies are spending more on defense. However, the economic fallout of the Covid-19 pandemic could pose new challenges to this nascent progress. Regardless, as Shields of the Republic points out, U.S. leaders during the Cold War did not expect defense spending equality because asymmetric alliances would allow the U.S. to, in part, shape allied defense policies.[5]

It is useful to recall that the construction of alliances at the start of the Cold War was not purely altruistic, they were meant to serve three key strategic purposes: forward defense, extended deterrence, and allied assurance and control. Shields of the Republic offers a convincing case that these strategic purposes remain relevant in order to prevent the formation of spheres of influence dominated by adversaries that would inhibit access to economic opportunities of Europe and Asia and thereby endanger U.S. security and prosperity. [6] However, the ability of the U.S. to continue to achieve these strategic goals, in the face of re-emerging adversaries who use non-military coercion effectively and have made U.S. alliances themselves strategic targets, remains uncertain. For those who subscribe to popular notions of strategic restraint, Shields of the Republic makes a cogent case for robust engagement and is sure to generate useful debate.[7]

The contours of the engagement Rapp-Hooper proposes includes updates to thresholds for collective defense, holding the line in Europe while Russia declines, developing a sophisticated economic strategy in the Pacific, reallocating funds provided for the Middle East to East Asia from the Foreign Military Financing program, and bolstering both funding and capabilities for the State and Treasury Departments.[8] These ideas, among many others, harmonize well with the explicit call in the National Defense Strategy to strengthen U.S. alliances and offers readers a thoughtful toolbox to draw on while re-forging these shields.

While Shields of the Republic posits many interesting ideas for strengthening U.S. alliances and their efficacy, the book does not fully contend with several larger trends that may work against these efforts. First, those who argue in favor of robust, persistent strategic defense alliances will have to contend with waning public support for global engagement. The COVID-19 pandemic may increase calls from the wings of both Republicans and Democrats for foreign policy restraint and the prioritization of domestic investment to shore up infrastructure, health security, and societal resilience. Second, the economic impact of technological trends in additive manufacturing, robotics, shifting supply chains, growing energy independence from the Middle-East, etc., may decrease American interest in affairs overseas, further reducing the political and economic rationale to remain engaged in global security. Further, given the dispersion of power and technology, the cost of intervention, power projection, and forward defense will rise. For those looking to understand these larger economic and technological trends and their implications, Deglobalization and International Security by T.X. Hammes offers detailed analysis and greater context. Readers would also do well to consider Stanley Sloan’s Defense of the West, and Victor Cha’s Powerplay, for a useful examination of the foundational principles and the political glue that holds our NATO and Pacific alliances together, sometimes in spite of severe crises.

Shields of the Republic is a fresh, accessible, and adroit examination of U.S. alliances that explores critical questions about the U.S. role in the world, its alliances, and the emerging great power competition that clouds the horizon. It also largely dispels the fog of misunderstanding about the political and financial costs of allies and their risk of entanglement, abandonment, or entrapment. It is an essential read for strategists, policy planners, students of history, and concerned citizens alike.

As Shields of the Republic reminds its readers , the original architects of our 70-year-old alliances in Europe and Asia have passed. The generation living in the aftermath of World War II understood the value of these structures intrinsically. The most effective and efficient way to protect the American homeland and the economy was through global engagement and forward defense. Today, the barriers between nations and empowered subnational actors continue to shrink in the midst of a peacetime international system that is increasingly dominated by competition and coercion between great powers.

General Mark Milley, Chairman of the Joint Chiefs of Staff, has said there is a need to remember why NATO began in 1949: “Peace doesn’t happen by accident: It happens because of effort, resources, commitment, allies banding together… to maintain a strong cohesive alliance.”[9] Shields of the Republic implores its readers to recall the logic of those post-war policy planners—if the U.S. does not wish to become isolated, it will require permanent alliances re-forged and refit for the twenty-first century.

Brett Swaney is an Assistant Research Fellow at the Institute for National Strategic Studies at the National Defense University. The opinions expressed are his alone and do not reflect those of the National Defense University, the Department of Defense, or the U.S. Government.

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Header Image: NATO Flags (Kenzo Triboulliard/AFP)

Notes:

[1] Mira Rapp-Hooper, Shields of the Republic: The Triumph and Peril of America’s Alliances (Cambridge, Massachusetts: Harvard University Press, 2020), 15.

[2] Moira Fagan and Jacob Poushter, “NATO Seen Favorably Across Member States,” Pew Research, February 9, 2020, available a https://www.pewresearch.org/global/2020/02/09/nato-seen-favorably-across-member-states/

[3]Heather Conley and Kathleen Hicks, “Pentagon Action to Withdraw from Germany Benefits our Adversaries,” The Hill, August 4, 2020, available at https://thehill.com/opinion/national-security/510477-pentagon-action-to-withdraw-from-germany-benefits-our-adversaries; David Welna, “Defense Secretary Esper Says U.S. Plans to Cut Troops in Germany by A Third,” NPR, July 29, 2020, available at https://www.npr.org/2020/07/29/896804140/defense-secretary-esper-says-u-s-plans-to-cut-troops-in-germany-by-a-third

[4] Michael J. Green and Jeffrey W. Hornung, “Are US-Japan Relations on the Rocks,” The Hill, July 17, 2020, available at https://thehill.com/opinion/international/507880-are-us-japanese-relations-on-the-rocks; Lara Seligman and Robbie Gramer, “Trump Asks Tokyo to Quadruple Payments for U.S. Troops in Japan,” Foreign Policy, November 15, 2019, available at https://foreignpolicy.com/2019/11/15/trump-asks-tokyo-quadruple-payments-us-troops-japan/

[5] Rapp-Hooper, Shields of the Republic, 79.

[6] Rapp-Hooper, Shields of the Republic, 15.

[7] For more on strategic restraint, see Barry R. Posen, Restraint: A New Foundation for U.S. Grand Strategy (Ithaca, NY, Cornell university Press, 2015); Christopher A. Preble, The Power Problem: How American Military Dominance Makes Us Less Prosperous, Less Safe, and Less Free (Ithaca, NY: Cornell University Press, 2009); John J. Mearsheimer and Stephen M. Walt, “The Case for Offshore Balancing: A Superior U.S. Grand Strategy,” Foreign Affairs 95 no. 4 (2016): 70-83.

[8] Rapp-Hooper, Shields of the Republic, 178-192.

[9] Jim Garamone, “NATO Nations Cannot Be Complacent, Milley Says,” U.S. Department of Defense, DOD News, January 14, 2020, available at https://www.defense.gov/Explore/News/Article/Article/2056782/nato-nations-cannot-be-complacent-milley-says/