Onset of Armed Conflict: A New List for the period 1946–2004, with Applications

The author presents a new list of conflict onsets based on the Uppsala/PRIO Armed Conflict Dataset (ACD), designed to address the lack of robustness in conflict literature caused by arbitrary coding decisions. The dataset allows researchers to vary the casualty threshold (
) and the minimum period of peace required before a new conflict is coded between old adversaries (). To demonstrate the utility of this framework, the author re-analyzes the findings of Hegre et al. (2001). The results indicate that while the effect of proximity to regime change on conflict risk is robust across different definitions, the perceived war-proneness of semi-democratic regimes is not robust and varies depending on the onset definition used.

• The new dataset provides a more inclusive list of 275 conflict onsets, significantly higher than the 127 and 145 onsets found in datasets by Fearon & Laitin (2003) and Sambanis (2004), respectively.
• The author proposes a flexible operational definition of conflict onset where the casualty threshold (
  ) and the intermittency threshold (), which can range from two to nine years, are adjustable by the user to test robustness.
• A re-analysis of Hegre et al. (2001) using the new framework shows that the relationship between proximity to regime change and the risk of conflict onset is robust, with a country experiencing recent regime change being 80-100% more likely to experience an onset.
• The finding that semi-democratic regimes are more prone to conflict is not robust, as the results are dependent on the specific definition of onset used and the number of observations included.
• Proximity to previous conflict, economic development, and population size are identified as consistently robust predictors of conflict onset across various model specifications.
• The author argues for a 'country-day' design over the standard 'country-year' format to better distinguish between cause and consequence when events occur within the same year.

APA

Strand, H. (n.d.). Onset of Armed Conflict: A New List for the period 1946–2004, with Applications. Peace Research Institute Oslo. https://cdn.cloud.prio.org/files/48029a5d-4a06-4be4-ad9c-c37835dde4e0/Onset and Duration Manuscript.pdf?inline=true

Chicago

Strand, Håvard. Onset of Armed Conflict: A New List for the period 1946–2004, with Applications. Peace Research Institute Oslo, n.d. https://cdn.cloud.prio.org/files/48029a5d-4a06-4be4-ad9c-c37835dde4e0/Onset and Duration Manuscript.pdf?inline=true.

Wikipedia

{{cite report |last1=Strand |first1=Håvard |title=Onset of Armed Conflict: A New List for the period 1946–2004, with Applications |publisher=Peace Research Institute Oslo |url=https://cdn.cloud.prio.org/files/48029a5d-4a06-4be4-ad9c-c37835dde4e0/Onset and Duration Manuscript.pdf?inline=true |access-date=23 October 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{strandndonset, author = {Strand, Håvard}, title = {{Onset of Armed Conflict: A New List for the period 1946–2004, with Applications}}, institution = {Peace Research Institute Oslo}, url = {https://cdn.cloud.prio.org/files/48029a5d-4a06-4be4-ad9c-c37835dde4e0/Onset and Duration Manuscript.pdf?inline=true}, urldate = {2026-10-23}, note = {Indexed by Climate Insights Directory} }