Conflict categories

1. Repression

Repression refers to the use of violence by state forces against civilians or protesters. Understanding repression is essential to assessing how governments respond to dissent, protests, and disorder. These actions often signal broader patterns of state control, civil rights, and human rights violations, and may escalate into broader political crises, potentially leading to insurgencies or other forms of conflict. 

To define repression, we examined the role of state actors in perpetrating violence against civilians and protesters. ACLED data already classifies events by disorder type — indicating whether an event is politically violent in nature — and actor interactions. This allows analysts to highlight violent events where state forces specifically interact with civilians or protesters across all event types (except for events that do not involve the use of force or violence).

The repression category consists of all political violence events that include an interaction between state forces (actor type 1) and civilians or peaceful protesters (actor type 7 or 6, respectively), across any disorder type except Strategic Developments. This typically includes sub-event types like “Abduction and forced disappearance,” “Excessive force against protesters,” or “Sexual violence,” offering a consistent lens into state-based repression across countries and time.

Since 2020, the global rate of repression has steadily increased, reaching its highest level in 2024, with Myanmar recording the highest number of repression events.

2. Insurgency

Civil wars and domestic armed conflicts often unfold in various forms. The insurgency category is intended to recognize that many acts by rebel groups occur outside the traditional conflict between insurgents and state forces. These varied acts reflect the many tactics insurgents use to assert control, extract resources, or punish opposition. Additional and common acts include violence targeting civilians, airstrikes, abductions, looting, and other non-violent strategic developments. This creates a comprehensive view of insurgent activity, including direct confrontations, strategic actions, and indirect violence. Understanding the full scope of rebel group activity is key to analyzing prolonged instability, governance breakdowns, and the challenges faced by civilians in affected areas. 

To define insurgencies, ACLED leveraged its actor interaction codes, specifically identifying all events involving rebel groups and at least one group coded as ACLED’s interaction code 2 (rebel group). Unlike traditional measures of armed conflict that consider only battle events, our approach includes all forms of rebel activity and allows ACLED users to isolate and monitor the evolution and scope of insurgencies globally.

Many of the world’s longest-running insurgencies are based in Africa, where there has also been a significant shift in technology in recent years, with increasing use of remote violence and airstrikes within domestic wars.

3. Atrocities

Atrocities are episodes of large-scale intentional killing of civilians and are among the most severe manifestations of political violence. These events often reflect deliberate strategies to inflict mass suffering, and they are associated with forced displacement, humanitarian crises, and long-term societal consequences. Identifying and tracking atrocities is critical for early warning, accountability, and humanitarian response.

Using ACLED’s existing categorization of “Violence targeting civilians” (VTC), atrocities are those events of VTC with 10 or more reported fatalities. Considering that ACLED employs a conservative methodology for coding fatalities, this threshold distinguishes mass killing events from isolated events with a low number of fatalities. The definition aims to be conservative yet sensitive to significant escalations in violence.

The atrocities category includes all VTC events that meet the threshold of 10 or more reported fatalities. This allows for a standardized way to isolate high-fatality civilian attacks across time and geography, supporting analytical efforts to track trends in mass violence and to inform humanitarian and legal interventions.

While atrocities can occur in any region, recent years have seen particularly high rates since late 2022 and with the onset of the conflict in Gaza and specifically (but not exclusively) in the widespread loss of Palestinian lives. The increasing use of airstrikes and drones has further exacerbated civilian casualties in these contexts. Otherwise, Africa has a substantial and ongoing high rate of atrocities despite having a relatively lower rate of events compared to other world regions, indicating that mass death events are more frequent in Africa compared to other areas. 

4. Terrorist activity

The definition of terrorism has often been influenced by politics, ideology, or the perceived intention of perpetrators. Our approach to defining terrorism focuses on the patterns of behavior and, specifically, the systematic targeting of civilians by armed groups. By focusing on the level of civilian targeting committed by armed groups relative to the annual global benchmarks, we provide a transparent, replicable method for categorizing terrorism based on the yearly actions of armed groups, as recorded in ACLED data.

ACLED defines terrorist activity through an actor-based, two-step process. First, we calculate the global baseline for VTC as a proportion of all political violence events involving named non-state actors in a given calendar year. Second, any non-state armed group that exceeds this VTC rate within a conflict context, represented by the country variable, and is involved in at least 50 political violence events during the same year will be designated as a terrorist group to ensure a sufficient sample to classify actor behavior. Once designated, all events involving that actor within that year and country are categorized as terrorist activity, including engagements with state forces and other armed groups, so users can investigate the entire scope of activity involving these groups.

Therefore, the terrorist activity category reflects political violence events involving non-state armed groups that were designated as terrorist groups for that year and country. In other words, actors that satisfy the following criteria for each year: 

1. Committing VTC at a rate higher than the global annual baseline.
2. Being involved in at least 50 political violence events that year. 

This approach allows for actors to enter or exit the terrorist group designation based on evolving behavior and avoids fixed or ideological criteria. Designations are recalculated and applied once each year in January. For the current year, terrorist designated groups retain their label based on the year prior until recalculation. A separate actor-level file includes the list of all designated actors per country and year since 2020.

The "Terrorist activity" category includes Unidentified armed groups (UAGs). UAGs are not included in the baseline calculation because, on a global level, they are common and represent diverse and mostly unrelated domestic armed groups. However, on the country level, UAGs can represent a distinct set of groups engaging in terrorism. Such UAGs can be designated as terrorist groups through the same methodology as other actors: When they, per country and per year, conduct above-average rates of civilian targeting and are responsible for more than 50 political violence events.

The category also includes mercenary groups and private security firms like the Wagner Group (actor type 8) but does not include (foreign) state forces or international organizations.

This transparent and replicable approach, based on patterns of armed group behavior, does not mirror existing classification schemes that rely on sanction lists or motives behind attacks. It identifies all groups that are prolific and systemic in their targeting of civilians, allowing users to understand terrorism based on observable patterns rather than ideology. 

5. Foreign military engagement

There is an increasing amount of state (i.e., state military) conflict outside domestic borders (e.g., inter-state conflict and cross-state conflict). ACLED categorizes these conflicts as "Foreign military engagement," which refers to all violent actions and strategic developments committed by state forces outside of their own territory. In addition to conflict outside of their domestic borders, including inter-state and cross-state conflicts (e.g., Russia-Ukraine), conflicts where foreign state forces engage with domestic non-state actors — such as rebel groups or political militias — are included. For example, a country’s military (e.g., Israeli Defense Forces) engaging with political militias in another country’s territory (e.g., Hezbollah in Lebanon) would be included in this category.

Building on ACLED’s categorization of actor types, foreign military engagement is defined as all events involving government and military actors coded as "External/Other forces" (interaction code 8), excluding foreign mercenary groups and private security firms like the Wagner Group and civilian international organizations that also fall under actor type 8.

This category encompasses a broad spectrum of activities by external forces outside their home countries, including both violent incidents like armed clashes and violence against civilians, and strategic shifts such as non-violent territorial transfers.