The nature of world politics is changing: “We are living in an era of interdependence”. Power and Interdependence (4th Edition), written by Robert O. Keohane and Joseph Nye, has provided a theoretical model of the international political system based on the interconnectedness and interdependence among international relations (IR) actors. This is a new approach, challenging the traditional theory by explaining international politics.

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    The two authors focus on analyzing “Interdependence” based on 02 main points: (1) definition of Interdependence, and (2) the relation between power and interdependence. Interdependence in world politics is defined as “situations characterized by reciprocal effects among countries or among actors in different countries.” Emerging in the post-World War II period along with the development of international transactions, the effect facilitated bilateral and multilateral cooperation, creating and improving interconnectedness among nations. However, we need to distinguish between interconnectedness and interdependence. In an interdependence relation, the related actors must be associated with certain security and economic effects when that of the interconnectedness is unconsidered. The former strategic interdependence between the United States and the Soviet Union during the Cold War, amended based on the general threat of nuclear destruction, has shown that interdependence depends not only on mutual benefits but also the actor’s value and the nature of the relations.

 

      Power has a decisive role in the interdependence of international politics. It is given that power can be thought of as the ability of an actor to control others’ actions, or to control the outcomes. The asymmetrical interdependence is also a source of power as changes in the relationship (which the actor may be able to initiate or threaten) will be less costly to that actor than to its partners. The role of power in interdependence is indicated in two dimensions: sensitivity and vulnerability. Sensitivity involves degrees of responsiveness within a policy framework, while vulnerability provides adaptability and long-term adjustment costs. For example, the increased oil prices during the 1970s had a severe impact on the economy dependent on oil imports, such as Japan and Western Europe, revealing these actors’ vulnerability. The United States, despite also suffering from oil shortages and inflation, was less damaged when compared to former regions due to its relatively lower oil-importing rate. The sensitivity of interdependence is further shown through the actors’ responsiveness in the same oil crisis: nations being able to shift into alternative energy resources, such as coal and natural gas, experienced less costly effects than those lacking such options. This distinction underscores a critical insight in international relations: power is not solely derived from resource capability, but also from the ability to amend policy, mitigate risks, and capitalize on opportunities embedded in international cooperation.

 

      The assumptions about world politics will profoundly affect how we perceive and explain world affairs. Realism, highly dignifying military power, and national security dominated in the postwar period. However, the limit of realism was revealed when it comes to collaboration and interdependence. Complex interdependence is suggested as a theoretical counterpoint and comes closer to reality. The point is whether complex interdependence provides a more accurate reflection of the present than traditional realism.

 

         On the one hand, for political realists, international politics is a struggle for power, dominated by organized violence. As always, being in a state of security dilemma, states worldwide need to actively strengthen the arms race to secure their survival, while international organizations play marginal roles in such a realist world. On the other hand, complex interdependence characterized world politics based on three main assumptions: (1) The multi-channel connection among government, organization and social networks; (2) The absence of clear hierarchy international politics: military security no longer dominates, domestic and foreign issues are addressed more flexible; and (3) the diminishing utility of military force, especially in addressing non-military issues such as climate change or international trade.  In today's world, phenomena such as multilateral cooperation, non-traditional security, and the growing influence of non-state actors are challenges that realism struggles to explain, whereas complex interdependence provides a more comprehensive and applicable analytical framework.

 

        To provide a generalised explanation for changes in the international regime, the two authors proposed four models, respectively based on changes in (1) economic processes, (2) the overall power structure, (3) the  issue structure, and (4) the influence of international organizations on state power. The economic processes model (1) emphasizes that technological and scientific breakthroughs, along with economic interdependence among nations, form the basis for changes in rules and institutions, thereby restructuring the system. And when it comes to domestic aspects, the authors pointed out that since the 1970s, countries have been motivated to shift away from unilateral, independent positions in order to take advantage of capital and labor flows, especially as public demand increases, necessitating growth in gross domestic product. As a result, even when national autonomy is at risk, the benefits of opening up to economic cooperation remain significant, including in cases where the relationship is asymmetrical, with one country possessing greater resilience and capability to adapt to changing circumstances than the other.
 

        In Model (2), changes in the international regime are explained as stemming from the erosion of hegemonic power. This means that there once existed a leading nation that saw itself as the main beneficiary of the long-term advantages of the regime and was willing to sacrifice certain short-term interests to preserve the system. However, that position was eventually challenged; for example, we can recall the case of the United States officially ending the convertibility of the dollar into gold, marking the decline of the Bretton Woods system. Meanwhile, Model (3), the issue-specific power structure, argues that power resources in one domain are ineffective when applied to other domains. In other words, military capability does not translate effectively into economic influence, and economic power relevant to one issue may be irrelevant to another. For instance, U.S. dominance declined more rapidly in the 1970s in the area of oil, even though the United States was militarily and economically stronger than Middle Eastern oil producers. It could not persuade OPEC countries to lower oil prices due to an imbalance of power in the energy sector. As for Model (4), the book emphasizes the role of networks and norms in shaping state behavior. In this model, international organizations are treated as independent variables that influence regime change, stabilize existing regimes, and make them resistant to change, even by powerful states.
 

         Theory is a set of arguments based on causal propositions. In the context of today's globalization, although written as early as the 1970s, the arguments and predictive power of Keohane-Nye's work have proven to be more relevant and dominant than other theoretical approaches. For example, organizations such as the United Nations (UN), the World Trade Organization (WTO), and the International Monetary Fund (IMF) operate based on interdependence, where power is distributed among various actors rather than relying solely on military strength. Another illustration is the U.S.–China trade war, which demonstrates how one country’s economic policy can impact the global market, supply chains, and diplomatic relations. Viewed through the lens of the four models explaining regime change mentioned earlier, this trade conflict took place amid significant global shifts in science and technology, most notably China’s rapid rise in both technological and economic spheres. Meanwhile, the United States, traditionally the leader and protector of the global economic and trade system, “the primary beneficiary of the regime’s long-term benefits and willing to sacrifice short-term interests to uphold the system”, has seen its hegemonic position challenged and eroded. Furthermore, the role of international organizations in setting norms and regulating participant behavior, represented here by the WTO, has failed to serve as an effective intermediary in resolving the dispute. As a result, the field of international economics has entered a state of instability and transformation.

 

     Based on the concept of “interdependence”, Keohane and Nye applied this framework to explain the phenomenon of “globalization” and examine how nations respond to the increase of interdependence in a global context. Globalization is essentially the expansion of globalism, characterized by the development of interconnectedness: density and scope of interconnectedness on a global level. Analyzing the two concepts of “sensitivity” and “vulnerability”, Keohane and Nye supposed that their values remain relevant in the context of globalisation. However, they emphasized the significant effects of vulnerability on power distribution compared to “sensitivity.” While “sensitivity” refers to the costly effects of nations’ responses to changes within an unchanged framework of policy, “vulnerability” reflects the costs associated with policy adjustments needed to respond to such influences. For example, a rise in global interest rates may adversely affect a domestic economy, prompting the state to consider the costly effects of policy adjustments. If costs of adjustment are substantial, the relationship goes beyond sensitivity to vulnerability. Vulnerability interdependence is particularly important from a political standpoint since it implies that agents are constrained by interdependence to make choices. Meanwhile, other agents leverage the asymmetrical vulnerability to enhance their power to get the outcome. 
 

      Besides, the two authors highlight the information revolution as an intervening variable, promoting the globalization process. The quick dissemination of information lowers the costs of transmission and allows access to information for all agents, which increases the influence of soft power. Globalization and information revolution have become an irreversible dynamic, emphasizing the role of cooperation in addressing trans-border issues.

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(Posted in June 2025)​

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AUTHORS

Do Hoang Ngoc Ha, Faculty of International Politics and Diplomacy, 50th cohort, Diplomatic Academy of Vietnam.

Dau Le Minh Hanh, Faculty of International Politics and Diplomacy, 50th cohort, Diplomatic Academy of Vietnam.

Sam Thanh Hang, Faculty of International Politics and Diplomacy, 50th cohort, Diplomatic Academy of Vietnam.

 

GRAPHIC DESIGNER

Nguyen Thi Hong Van, Faculty of International Politics and Diplomacy, 51st cohort, Diplomatic Academy of Vietnam.

 

REFERENCE

Keohane, R.O. and Nye, J.S. (2012). Power and Interdependence. 4th ed. Pearson, pp.34, 223–234.