The Strategic Logic of Nuclear Delivery System Diversification

About the Project

Why do nuclear-armed states choose to diversify or narrow their arsenal of delivery systems? This question lies at the heart of nuclear strategy, yet remains surprisingly underexplored in the academic literature. While scholars have extensively examined decisions to acquire or abandon nuclear weapons entirely, far less attention has been paid to the critical choices states make about how to deliver them.

This doctoral project investigates the strategic, technological, economic, and political factors that drive nuclear powers to expand or contract their range of delivery options. The UK's abandonment of the Blue Streak missile program, followed decades later by its transition to a purely submarine-based deterrent, offers a striking example of narrowing. France's elimination of land-based missiles in favor of sea and air platforms represents another significant contraction. By contrast, Pakistan's recent emphasis on cruise missiles alongside ballistic systems exemplifies diversification, as does China's revival of bomber-delivered nuclear weapons after decades of neglect.

The project will develop and test competing theoretical frameworks to explain these divergent paths. Does diversification reflect responses to adversary missile defenses, or does it signal attempts to enhance crisis stability through flexible response options? When states narrow their delivery portfolios, are they driven primarily by cost constraints, technological failures, alliance commitments, or strategic calculations about second-strike survivability? How do domestic political factors, bureaucratic interests, and arms control agreements shape these decisions?

The successful candidate will conduct comparative historical analysis across multiple nuclear powers, drawing on archival research, elite interviews, and declassified strategic documents. Cases will likely include the UK, France, the United States, Soviet Union/Russia, China, India, and Pakistan, though the precise case selection will be developed collaboratively. The project offers flexibility for candidates to focus on particular regions, time periods, or theoretical approaches depending on their interests and language capabilities.

This research promises significant contributions to nuclear strategy, international security studies, and foreign policy analysis. It will inform contemporary policy debates about force structure modernization, arms control verification, and the stability implications of emerging technologies like hypersonic delivery systems. The findings will be relevant to defense planners, arms control practitioners, and scholars seeking to understand how states balance military effectiveness, economic constraints, and strategic signaling in their most consequential security decisions.

The ideal candidate will have a strong background in international relations theory, security studies, or strategic studies, along with demonstrated research skills and genuine intellectual curiosity about nuclear weapons policy.

University of Reading:

The University of Reading, located west of London, England, is ranked at 194 globally, according to the QS World University Rankings 2026. 98% of research at the University is of international standing (REF 2021, combining the University’s world leading, internationally excellent and internationally recognised submissions). The University’s main Whiteknights Campus is set in 120 hectares of beautiful, award-winning parkland, less than a 30-minute train ride to London Paddington and is approximately 30 miles from London Heathrow airport.

During your PhD at the University of Reading, you will expand your research knowledge and skills, receiving specialist supervision. We also provide dedicated training in important transferable skills that can help support your career aspirations. If you need to develop your academic English skills before you start your studies, then the University has an excellent International Study and Language Institute which can help with this.

Eligibility:

• Applicants should have a good bachelor’s degree (minimum of a UK Upper Second (2:1) or equivalent)/master’s degree in Politics or a strongly-related discipline.
• International applicants will also need to meet the University’s English Language requirements. We offer pre-sessional English courses that can help with meeting these requirements.

The University of Reading is committed to a policy of equal opportunities and non-discriminatory treatment for all members of its community.

How to apply:

Submit an application for a PhD in Politics via our online application system.

Further information: Department of Politics and International Relations PhD webpage

Enquiries: Dr Joseph O’Mahoney, email: j.p.a.omahoney@reading.ac.uk

Funding Notes

We welcome applications from self-funded students worldwide for this project.

If you are applying to an international funding scheme, we encourage you to get in contact as we may be able to support you in your application.