arXiv subjects

Olivier J. Walther

Publications and source records attributed to Olivier J. Walther.

6 recordsLinked to original sources

arXiv2026

Changing Geographies of Violence in North and West Africa

This paper analyses spatial trends in armed conflicts in North and West Africa. It shows that all types of violence saw a significant increase in 2025. However, these violent incidents are distributed very unevenly across the region: while conflict is at its lowest in North Africa, the vast majority of violent incidents and victims are concentrated in five West African countries: Nigeria, Cameroon, Mali, Burkina Faso, and Niger. Coastal countries are experiencing a very mixed picture: jihadism is not advancing as a front, from the Sahel toward the Gulf of Guinea, and most of the violence stems from local disputes, ethnic conflicts, and banditry. Second, the spatial indicator developed by the OECD/SWAC to track the evolution of this violence confirms that the conflict landscape is expanding at its margins and intensifying at its center. Even more concerning is that peripheral areas are increasingly being drawn directly into well-established conflict zones, rather than going through a gradual, low-intensity transition phase. The geography of expansion is shifting from a diffuse, low-intensity spread toward peripheral areas to a rapid outward expansion from dense, well-established conflict hotspots. The local indicator used in the report suggests that violence continues to spread to new locations at the margins of established conflict zones. At the heart of these zones, tensions are intensifying relative to their historical baseline levels, and a growing number of regions have experienced clashes for a decade or more. Projections indicate that the intensity of violence is expected to increase in 2026, reaching more than 15,000 incidents and more than 32,500 deaths. Much of the increase is explained by the growing number of conflicts in Nigeria. In the Sahel, fatalities should increase in Mali and decrease in Burkina Faso.

stat.AP↗

arXiv2026

Cities and political violence in West Africa

This paper examines how political violence in West Africa is distributed between urban agglomerations and their surrounding areas using spatially disaggregated conflict and population data. Covering seventeen countries from 2012 to mid-2025, the analysis shows that political violence remains clearly tied to cities and their peripheries with the majority of violence occurring within and around urban agglomerations. Large cities record the highest number of incidents within their boundaries, while smaller towns, which are more frequently situated near borders, typically experience higher levels of violence outside their boundaries. However, urban-centric violence has also declined since 2012, indicating a progressive ruralization of conflict. These findings provide important regional context to the urbanization of conflict narrative by showing that West African insurgent movements use both urban and rural environments strategically. They also underscore the ongoing vulnerability of peripheral populations and the need for mobile and community-based security approaches outside major cities. Finally, they highlight the importance of strengthening border infrastructure, transport networks, and civic institutions as tools of both development and security.

econ.GN↗

arXiv2026

Transnational political violence in African borderlands

This paper examines the relationship between borderlands and political violence in Africa. Using spatiotemporal data on conflict events from 1997 to 2024 alongside the innovative OECD Spatial Conflict Dynamics indicator (SCDi), it suggests that borderlands see more conflict than non-borderlands. Political violence tends to decrease very rapidly with the distance to borders in Africa. The share of violent events recorded in borderlands varies over time and mirrors the cycles of violence that affect specific regions. It was very high in the early 2000s due to the wars in the Gulf of Guinea and Great Lakes region, declined for less than a decade, and increased substantially in the 2010s. Finally, the paper shows that when conflicts diffuse across borders, they tend to occupy a greater spatial extent, rather than relocate from one side of the border to the other.

econ.GN↗

arXiv2023

How international research teams respond to disruption in their mobility patterns

Combining social network analysis with personal interviews, the paper examines how the social structure and internal composition of three Africa-focused international research networks contributes to their resilience. It shows that research networks are structured around a small number of highly influential coordinators. This structure facilitates information exchange and trust between countries and across fields. The study also suggests that the surveyed teams tend to exchange information or trust each other irrespective of their social and professional attributes, indicating that diversity is key to understanding their responses to major shocks such as the COVID-19 pandemic. In a second part, the paper analyzes how the spatial constraints imposed by distance and borders affect their ability to function internationally. It shows that the probability of exchanging information, trusting each other, and co-publishing decreases considerably with distance and that research communities are more likely formed inside the same country than internationally. Interviews reveal that teams responded to travel bans and border closure by emphasizing what they already did best, suggesting that resilience should be considered as an evolutionary attribute of a system.

cs.SI↗

arXiv2022

Introducing the Spatial Conflict Dynamics indicator of political violence

Modern armed conflicts have a tendency to cluster together and spread geographically. However, the geography of most conflicts remains under-studied. To fill this gap, this article presents a new indicator that measures two key geographical properties of subnational political violence: the conflict intensity within a region on the one hand, and the spatial distribution of conflict within a region on the other. We demonstrate the indicator in North and West Africa between 1997 to 2019 to show that it can clarify how conflicts can spread from place to place and how the geography of conflict changes over time.

physics.soc-ph↗

arXiv2019

Social networks and geography: a review of the literature and its implications

The spatial metaphor of the network along with its accompanying abstractions, such as flow, movement, and connectivity, have been central themes throughout the relational turn in human geography. However, to date networks in geography have been primarily explored either through actor-network theory or assemblage thinking, both of which embrace the network metaphor without specifically and formally interrogating networks themselves. We seek to problematize the treatment of networks in geography by exploring the largely underutilized literature on social networks as an alternative to the now dominant actor-network and assemblage frameworks. Our paper discusses the conceptual connections between key concepts in geography, such as place, distance, scale, and power, and those in network theory, such as centrality, density, and homophily. Voluntarily written from the periphery of human geography, our paper opens new directions for geographers that are interested in more than the metaphor of the network.

cs.SI↗