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The International Spectator 1/2004

ESDP and the Structure of World Power
Barry R. Posen*

Disputes within the transatlantic alliance over the necessity and timing of the 2003 US-led war with Iraq and the modalities of the reconstruction of that country have produced doubts about the future of transatlantic relations. This article will consider thisfuture from a theoretical point of view: what does “realism,” the oldest and (arguably) most reliable theory of international politics, suggest about the future of transatlantic relations? What are the larger forces that shape this issue? These questions will be examined in light of one of the more peculiar developments of the last decade: the European Security and Defence Policy (ESDP). Why does theEU, absent the Soviet Union, and largely sheltered under the umbrella of the mighty United States, choose to spend time and resources on such a project?

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Barry R. Posen is Ford International Professor of Political Science at the Massachusetts Institute of Technology (MIT), Boston. This is a revised version of a paper presented at the conference on "Transatlantic Security Cooperation: FacingThe New Challenges". Held in Rome on 17 November 2003, the conference was jointly organised by the IAI, the European Union Institute for Security Studies (EU-ISS) and the Centro Militare Studi Strategici (CeMiSS) with the support of the German Marshall Fund of the United States (GMF), the Compagnia di San Paolo, Turin, the Rome office of the Friedrich Ebert Stiftung and the US Embassy in Rome.Copyright © 2004 by the Istituto Affari Internazionali. Vol. XXXIX, pp. 5-17.

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6 ESDP and the Structure of World Power

Structural realism and unipolarity Tenets of realism In its modern guise, “structural realism” is an analytical, not a prescriptive theory. It tells us a little bit about how international politics, especially great power politics, works.Structural realism depicts the world as an anarchy – a domain without a sovereign. In that domain, states must look to themselves to survive. Because no sovereign can prevent states from doing what they are able to do in international politics, war is possible. The key to survival in war is military power, generated either internally or through alliances, usually both. States care very much abouttheir relative power position because power is the key to survival. They try to increase their power when they believe they can do so without too much risk. They try especially hard to preserve the power they have. Because war is a competition, power is relative. One power’s position can deteriorate due to another power’s domestic or foreign success. When another power increases its capacitiesthrough either internal or external efforts, others have incentives to look to their own position. Structural realism does not predict that all powers will behave this way all the time, but those who do will likely survive and those who do not will likely suffer and perhaps disappear from history. 1 States that get the message may choose from an array of possible strategies – all problematic. States ofthe first rank are generally expected to bal ance against the greatest powers, figuring that failure to look to their own capacities will invite future predation.2 They will build up their capabilities and form balancing alliances. Sometimes, however, great powers may choose to pass the buck, that is, look to their own national capacities to the extent that they can but hope, bet or scheme to getother great powers to shoulder the majority of the risks and costs of containing the greatest power.3 If one state expands its power, others may try to bandwagon with it in the hopes of getting a good deal. Realists on the whole expect small, weak states to band1

On realism, see K. N. Waltz, Theory of International Politics (Reading, MA.: Addison-Wesley, 1979) pp. 102-28; J. J. Mearsheimer,...