How Conflicts Spread: Why Local Wars Become Regional Crises

Many modern wars do not stay where they started. Prominent conflicts that have arisen in the last decade, such as those in Sudan, Ethiopia, and across the Sahel, have not remained self-contained domestic crises. Each is embedded in a regional network of refugee flows, sanctuary territory, weapons pipelines, financing channels, and external sponsorship that links multiple states into a single conflict system. Understanding these wars increasingly means understanding how conflict spreads across borders. 

The rising risk of conflict spread

The risk of conflicts spreading has been exacerbated by three structural shifts:

1. 1. There are more conflicts in more places than at any point since World War II, and the death toll from conflict has risen accordingly.  
2. 2. Conflicts are less likely to end in decisive victories or peace agreements.
3. 3. New technologies are lowering the barrier to participation for state and non-state actors alike.

Together, these structural shifts make conflict spread more likely. As conflicts become more interconnected, local wars increasingly evolve into regional crises as their effects extend beyond national borders through political, social and economic systems.

How local wars become regional crises

Modern armed conflict rarely stays within a single country. Many existing conflicts are embedded in regional networks of refugee movements, cross-border kinship, foreign sponsorship, illicit finance, and ideological affiliation. The footprint of a contemporary civil war routinely extends well beyond the country in which fighting takes place. The peacefulness of neighbouring states is now shaped largely by events those neighbours do not control.  

Early studies of how conflicts spread treated geographic clustering as evidence of automatic ‘spillover’, comparing the spread of conflict to a medical infection. That framing no longer holds. The spread of conflict is neither inevitable nor driven by a single cause. It results from identifiable mechanisms, shaped by the strategic choices of states, armed groups, displaced populations, and ideological networks, and by how permissive the surrounding environment is. 

The mechanisms of conflict spread

The Global Peace Index 2026 groups these conflict spread mechanisms into three broad categories:

• Material factors move people, weapons, money, and fighters across borders.
• Relational factors link armed actors, ethnic groups and states to one another through ties that pre-exist any specific conflict.
• Conditioning factors, including state capacity, institutional quality and prior experience of contention, determine how vulnerable a given environment is when material and relational channels are activated.

Together, they provide a practical framework for analysing how conflicts spread across borders and why some regions are more vulnerable than others. 

Whether a given conflict spreads depends on which mechanisms are activated, on the density of cross-border ties, and on the institutional resilience of neighbouring states.

For a more detailed analysis of conflict spread and its underlying mechanisms, see the Global Peace Index 2026.