This report offers a framework exploring countries’ motivations when purchasing capabilities. Through eight case studies, the report describes the factors that shape a country’s decision to acquire military capabilities and the practical considerations in balancing trade-offs in cost, function, timelines for delivery, and other incentives to select suppliers and systems.

Understanding Partner Preferences in the Selection of Defense Capabilities

Case Studies Exploring the Selection of Alternatives to U.S. Solutions

Aidan Winn, Caitlin McCulloch, Jennifer D. P. Moroney, Beth Grill, Krystyna Marcinek, Casey Mahoney, Stephanie Pezard, David E. Thaler, Paul Cormarie

ResearchPublished Jun 16, 2026

Exporting arms to international partners is a core component of U.S. foreign policy and U.S. Department of Defense security cooperation. However, changes in the strategic environment and global defense marketplace complicate arms transfer. Although the U.S. defense industrial base remains dominant in this evolving strategic environment, changes in partner needs and priorities mean that the United States might be unable to meet sudden spikes in global demand. To implement the National Defense Strategy, the United States must increasingly anticipate partner defense needs, including identifying situations in which U.S. solutions will be unable to meet those needs.

Understanding how and why partners turn to third-party suppliers, and under which circumstances those decisions are consistent with U.S. interests, is an important objective. This report offers a framework exploring countries’ motivations when selecting capabilities from exporters. The authors present eight case studies of the selection of non-U.S. suppliers and the considerations that led to those decisions. This report describes the factors that shape the decision to acquire military capabilities and the practical considerations in balancing trade-offs in cost, function, timelines for delivery, and other incentives to select suppliers and systems.

This report is designed to highlight the factors that affect decisionmaking in acquisitions and inform discussions about the capability needs that U.S. partners and allies can best meet. These decisionmaking dynamics have implications for the training and education of the Defense Security Cooperation Agency (DSCA), which executes the U.S. Foreign Military Sales (FMS) program.

Key Takeaways

  • The Philippines’ purchase of advanced surveillance radar from Japan represents an opportunity for the United States to expand a trilateral U.S.–Japan–Philippines alliance, crucial to broader U.S. strategic interests.
  • Poland’s purchase of light attack aircraft from Korea allowed the former to support Ukraine while maintaining its own readiness with as little interoperability loss as feasible on compressed timelines.
  • A technically advanced U.S. ally can provide alternatives to U.S. systems to meet a partner’s needs, and production licensing can enable both an ally’s autonomy and interoperability with North Atlantic Treaty Organization partners.
  • The selection of a third-party supplier with a close relationship with the United States is reasonably compatible with U.S. interests and might be appealing to purchaser countries seeking to avoid aligning themselves with the United States.
  • The United States did not have a valid option to offer Egypt, but French-supplied corvettes allowed Egypt to buy a Western system instead of a Russian one. Partnering with third-party allies when a purchaser maintains a stronger defense relationship with that ally is likely advantageous for U.S. interests.
  • From an FMS global competitiveness perspective, there appears to be value in commercially derived systems that can be rapidly fielded and whose low cost enables them to be operationally relevant even in high-attrition environments.
  • DSCA should consider supporting partners pursuing non-U.S. solutions when the United States is not positioned to offer a solution and the purchaser will seek the capability from a geopolitical competitor and harm U.S. interests.

Recommendations

  • As weapon decisions increasingly require outside inducements, U.S. strategy would benefit from innovative thinking about which allies might be best positioned to provide the most-attractive incentives.
  • The framework laid out can help analysts identify the variety of factors that are contributing to partner decisions and understand the factors that motivate foreign partners’ acquisition decisions. It can also help analysts understand the interaction between security, political, strategic, and economic factors that are at the root of partners’ preferences.
  • This analytical framework can help the United States become more anticipatory of partner needs and preferences and make more–fully informed decisions about whether and in which cases it is consistent with U.S. interests to advocate for and encourage partners to seek out third-party suppliers.

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Winn, Aidan, Caitlin McCulloch, Jennifer D. P. Moroney, Beth Grill, Krystyna Marcinek, Casey Mahoney, Stephanie Pezard, David E. Thaler, and Paul Cormarie, Understanding Partner Preferences in the Selection of Defense Capabilities: Case Studies Exploring the Selection of Alternatives to U.S. Solutions. Santa Monica, CA: RAND Corporation, 2026. https://www.rand.org/pubs/research_reports/RRA2822-1.html.
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This research was sponsored by the Defense Security Cooperation Agency and conducted within the International Security and Defense Policy Program of the RAND National Security Research Division.

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