Sloan Lansdale

Sloan Lansdale

PhD Student, University of Maryland

Posts by Collection

portfolio

publications

The Politics of International Peace and Security: Introducing a New Dataset on the Creation of United Nations Security Council Subsidiary Bodies

Published in International Studies Quarterly, 2024

This paper introduces new data on the creation of subsidiary bodies (SBs) by members of the United Nations Security Council (UNSC) between 1972 and 2020. Delegation to SBs is one of the principal means through which the UNSC acts, and these bodies are designed to carry out crucial functions such as peacekeeping, implementing sanctions, and investigating crises. Yet, no research has systematically evaluated their creation, design, and use. Our dataset includes a typology of all proposed and created SBs as well as information about their purpose and design. After introducing the data, we empirically analyze the determinants of SB creation. Multivariate regression demonstrates that SBs are more likely to be created when the preferences of the permanent members are aligned. Moreover, stronger bodies are more likely to be created during periods of high preference alignment, while middle- and lower-strength bodies are less influenced by member alignment. These results provide unique evidence demonstrating how politics affects the choice of when and how the UNSC responds to global problems. Our data and analysis paint a picture of a more proactive UNSC than is commonly portrayed in the literature, and these data will enable scholars to further analyze UNSC action.

Recommended citation: Lugg, A., Lansdale, S., & Carcelli, S. (2024). The Politics of International Peace and Security: Introducing a New Dataset on the Creation of United Nations Security Council Subsidiary Bodies. International Studies Quarterly, 68(2), sqae060.

Putting Mass Atrocities on the Agenda: UNSC Response to Mass Atrocities

Published in ISA-Workshop on atrocity prevention strategies and tools, 2025

Under what conditions can we expect the United Nations Security Council (UNSC) to respond to mass atrocity events? While previous literature suggests that the UNSC responds based on the severity of the crisis, there is still great variation among cases at the highest levels of severity. While Rwanda received an international criminal tribunal, the atrocities at the end of the Sri Lankan Civil War never made it onto the UNSC agenda. I argue this variation stems from the considerations the Council President must make when setting the UNSC agenda. These considerations include more than the severity of the crisis but the preferences of salient audiences as well, including the target state, the international community, and their co-members of the council. To test my argument, I collected new data on UNSC response to 24 mass atrocities from 1989 to 2024. My findings will offer a framework for understanding the conditions under which the UNSC takes action on mass atrocities. By identifying how member states navigate the competing pressures of internal dynamics and external advocacy, this research provides insights into improving the predictability of UNSC behavior.

Under what conditions does preventive mediation occur in self-determination disputes?

Published in Journal of Peace Research, 2026

Mediation is a crucial instrument employed by external actors to resolve armed conflicts and mitigate violence. A large academic literature examines mediation in civil war, with analyses of which civil wars see mediation and what the effect of this mediation is. Many organizations express a commitment to conflict prevention, and engage in mediation to prevent the outbreak of armed conflict. There is much less research on when mediation is used as a tool of conflict prevention. We have collected new data on all mediation efforts in a random sample of 51 self-determination (SD) disputes from 1991–2015, which includes disputes that never experience armed conflict, as well as years before and after armed conflicts in disputes that do. We use these data to examine the conditions under which preventive mediation occurs in SD disputes. We develop a theoretical argument for when mediators are likely to offer mediation, and governments and representatives of SD groups are likely to accept it. We test this argument using our new data in two samples of SD dispute-years that are not in armed conflict. We find that mediation is more likely in dispute-years outside of armed conflict where SD groups are engaged in low-level violence and in disputes in countries that border other countries that are experiencing armed conflict and less likely in disputes in states that are permanent members of the UN Security Council or former French colonies. This analysis shows that mediators do engage in preventive mediation in disputes that they perceive as having a higher likelihood of escalation to armed conflict, but that they are constrained in their ability to do so by geopolitics.

Recommended citation: Cunningham, D. E., Bauer, L., Lansdale, S., & Lloyd, M. (2026). Under what conditions does preventive mediation occur in self-determination disputes?. Journal of Peace Research, xjaf033.

Rhetoric Passes, Action Fails: UNSC Response to Mass Atrocity Events

Published in ISA, 2026

The United Nations Security Council (UNSC) is the central body tasked with maintaining international peace and security, yet its responses to mass atrocity (MA) events are inconsistent. Existing research typically treats resolution adoption as a single process, yet distinct dynamics shape whether a resolution is proposed compared to if the resolution passes. This article argues that these stages reflect different incentive structures: proposing a resolution is shaped by reputational concerns, political distance from the target state, and international attention. Alternatively, passage requires collective agreement constrained by great-power politics. Using a dataset for 403 UNSC meetings on 17 mass atrocity events (1989-2024) and a two-stage model, I show that the advocacy and political distance drive proposal, while the passage is shaped by great power preferences. Failed resolutions thus function as expressive political acts rather than institutional failure, helping explain why the Council can appear simultaneously active yet ineffective in responding to mass atrocities.

talks

teaching

GVPT388- Undergraduate Research Assistantship Program

Undergraduate course, University of Maryland, Government and Politics, 2023

This course allowed high-performing students to develop and execute their research projects under the mentorship of a faculty member. I facilitated class meetings, lecturing the students on research design. I also held individual meetings with students to discuss their progress and provide feedback. Through this course, I am able to mentor a diverse group of students from project inception to completion and presentation in front of faculty and peers. I have taught in this position since Fall 2023.

GVPT309: From Declaration to Action: The United Nations and Human Rights

Undergraduate Course, University of Maryland, Government and Politics, 2024

I developed this course with the aim to teach students about the history and development of human rights through the lens of the United Nations as an institution. The course will track how the UN formalizes and promotes human rights through treaties and bodies under the UN umbrella. The course will also discuss how these norms disperse informally between states as well as domestically. Students will leave the course with the ability to identify and assess the efficacy of current international efforts to promote human rights through international organizations. Taught Asynchronously Summer 2024.

International Conflict Simulation

Undergraduate Activity, University of Maryland, Government and Politics, 2025

Heavily based on the classroom game developed by Dr.Nathan Sears, this simulation is designed to teach students key concepts in International Relations (IR), such as anarchy in the international system, the security dilemma, and strategic decision-making. Students will role-play as states in an anarchic international system, making decisions about resource allocation (armaments vs. enjoyment) and foreign policy (peace vs. war). The decisions students make, the outcomes they experience, and the frustration or elation they feel together become a touchstone you can return to when introducing new concepts or cases, connecting theory to something students have already experienced in the miniature. This shared experience prompts students to think deeply about their own decisions and those of others, and how those decisions mirror those of states in the international system more broadly. Extensions are provided to further emphasize the concepts of great power rivalry, private information, and international institutions.

GVPT200: International Political Relations

Undergraduate Course, University of Maryland, Government and Politics, 2025

I taught an introductory International Relations course synchronously online in Summer 2025. The course introduced students to core concepts in the field, including statehood, anarchy, security dilemmas, and the foundations of game theory, while also engaging with contemporary issues such as climate politics, international institutions, and the return of great power rivalry. To bridge theory and practice, I incorporated interactive simulations that placed students in the role of decision-makers, allowing them to experience firsthand the dynamics of the prisoner’s dilemma, the challenges of collective action, and the complexities of conflict negotiation. These activities encouraged students to connect abstract theories to real-world political challenges, while developing analytical and collaborative skills.