Although preventing atrocity crimes is far preferable to responding when the crimes are ongoing or after they have been committed, there are times when prevention has failed. The brutal legacy of the twentieth century, marred as it was by the Holocaust, the killing fields of Cambodia, the genocide in Rwanda and in Srebrenica and other events, underlined the profound failure of individual States to live up to their responsibilities and obligations under international law, as well as the collective inadequacies of international institutions. These tragedies pressed the need for a collective response that would protect populations by either stopping the escalation of on-going atrocities, or accelerating or prompting their termination.
Though the responsibility to protect populations against genocide, war crimes, ethnic cleansing and crimes against humanity lies primarily with individual States, the principle also underlines the responsibility of the international community to take collective action, in a “timely and decisive manner”, to protect populations from those crimes when States “manifestly fail” in their responsibilities. In these cases, responses to atrocity crimes can take the form of peaceful means under Chapters VI ad VIII of the United Nations Charter, or take the form of coercive means, including those foreseen in Chapter VII of the Charter.
Some may consider that prevention and response are at opposite ends of the spectrum. In practice, however, the two often merge. Putting an end to ongoing atrocity crimes in a particular situation should mark the beginning of a period of social renewal and institutional capacity-building aimed at making future violence less likely. In this way, an informed and calibrated response to atrocity crimes also serves prevention goals.
In addition, it may not always be possible to clearly determine whether an activity falls exclusively under a preventive or a responsive approach. In fact, a State’s responsibility to protect its populations from atrocity crimes, as well as the commitment of the international community to assist States in that responsibility, both entail elements of prevention and response, sometimes even at the same time. For instance, international assistance in the form of an international commission of inquiry to establish the facts and to identify the perpetrators of crimes and violations relating to the responsibility to protect can also constitute a timely and decisive response. At the same time, dispatching an international commission of inquiry can, through its mere presence in the State concerned, contribute to the prevention of further crimes and violations and thus serve as an international assistance preventive measure.