U.S. Alliance and Partner Networks

The Office of the Secretary of Defense asked the RAND Corporation to measure the strength and health of the United States' network of allies and partners. It did so with a view to determining how much the United States can continue to rely on that network in formulating and executing its defense strategy. Using network analysis, interdependence analysis, combinatorial optimization, and simulation, the RAND team constructed global networks representing diplomatic, military, and economic elements of national power in 1989, 2000, and 2017. The team then conducted an exploratory analysis of these networks separately and in combination. The team members compared the connections, centrality, interdependence, vulnerability to disruption, risk of conflict contagion, network depth, and U.S. access to network depth per dollar of U.S. assistance provided to allies and partners of the United States. This analysis suggests that the U.S. network remains strong and robust enough that the United States can probably continue to rely on it for the formulation and execution of its grand strategy for the time being. However, the authors identified more than two-fifths of the U.S. network's member states that had experienced changes in their levels of interdependence between 1989 and 2017 that could give decisionmakers in those countries grounds to question the continuing value of their alliance ties. This suggests that policymakers should pay careful attention to the strength of the U.S. alliance network going forward and to their approach to individual countries where shifts in dependence have been significant.