Atrocity prevention refers to a broad range of tools and strategies which aim to prevent the occurrence of mass killings and other large scale human rights abuses committed against civilians.

Although there are close similarities between atrocity prevention and many of the tools used in conflict prevention, there are also important differences.

Whilst the large majority of mass atrocities occur during armed conflicts, a significant number of instances of mass atrocities (one third of all cases since 1945) have in fact occurred in 'peacetime' contexts. What this means is that conflict prevention strategies which are focused on preventing armed conflict without addressing latent social conflict may not alone be enough to prevent mass atrocities. Furthermore, even in situations of ongoing armed conflict, where by definition conflict prevention has failed, work can still be done to prevent the occurrence of atrocities. Whilst in some contexts, resort to armed violence may appear to have some legitimacy- as a means of self-defence or of resisting oppressive rule, for example- atrocities on the other hand are never legitimate or justifiable.

The distinction between atrocity prevention and conflict prevention is therefore an important one. Nevertheless, conflict prevention and atrocity prevention can often be complementary. Firstly, although atrocities do sometimes occur outside of armed conflicts, a sizeable and growing majority occur during conflicts, with armed conflict often serving as an enabling factor for atrocities to be committed. Reducing the occurrence of violent conflict is likely to reduce the number of instances of mass atrocities too. Secondly, many of the tools and strategies employed by those working on conflict prevention can also be utilised to prevent mass atrocities. 

Crucially though, for the tools of conflict prevention and peacebuilding to be utilised effectively for mass atrocity prevention, a specific atrocities prevention analysis and strategy may be needed. Effective early warning systems, for example, are a crucial element of both conflict prevention and atrocity prevention. However, the indicators which signal the likely onset of violent conflict may differ significantly from those which signal a risk of atrocities occurring. Thus, a conflict prevention early warning system may 'miss' signs of the onset of mass atrocities. Similarly, whilst the principle of neutrality may underpin much peacebuilding and conflict prevention work, in the contexts of one-sided atrocities this may be less appropriate, and even act as a 'green light' to perpetrators.

Broadly speaking, atrocity prevention activities can be divided into three different spheres- those of prevention, response and recovery.

1. Prevention. Preventing atrocities occurring requires measures to identify and mitigate risks and to build resilience of societies to withstand those risks. This might include early warning systems, dialogue and trust building exercises, promoting human rights, the rule of law and democratic governance, strengthening civil society, and building legitimate, representative institutions.
2. Response. When atrocities are occurring, atrocity prevention must work to provide protection to at-risk groups, whilst seeking to dissuade perpetrators or potential perpetrators from committing further atrocities, documenting ongoing atrocities, and supporting the mitigation or resolution of armed conflict.
3. Recovery. Mass atrocities often occur cyclically. Cases of apparently one-sided atrocities may in fact actually be part of a long history of tit-for-tat violence. Thus, in the aftermath of atrocities, supporting recovery is vital in order to break this cycle and prevent future atrocities. This might include supporting justice and accountability, healing and reconciliation processes, political transition and economic recovery.

Following the horrors of Rwanda and the Balkans in the 1990s, the early 21st century has seen a growing recognition from the international community of the need to take action to prevent mass atrocities occurring. In 2005, all member states of the United Nations committed to the Responsibility to Protect (R2P) doctrine, a commitment to prevent genocide, war crimes, ethnic cleansing and crimes against humanity. In 2011, President Obama declared that preventing mass atrocities was a core US national interest and a moral responsibility. He ordered the creation of the US government's Atrocity Prevention Board. Governmental and civil society networks committed to atrocity prevention have been developing in Latin America, Asia, Africa, and Europe.

It is also widely acknowledged that local actors have a crucial role to play in atrocity prevention, as they are often on the frontlines of atrocity situations and can act as ‘first responders’ to warning signs or trigger events. Atrocities also often have deep historical roots, and local actors are usually best placed to understand and devise sustainable solutions to those legacies. Outsiders may struggle to grasp the historical legacies fuelling atrocities, and as a result impose solutions that fail to adequately address the structures of exclusion and violence which facilitate the perpetration of atrocities. International interventions should therefore as much as possible aim to develop local capacity and support local ownership of atrocity prevention strategies.