Since the end of the Cold War, the conditions in which military action takes place have changed considerably, under the influence of a range of international factors.

Following the uneven progress of globalisation and the difficulties international organisations have faced in controlling tensions in the world, the nature of conflicts has changed, and they frequently involve international non-state actors. Advanced technologies, in the areas of information and certain types of weapons, have become available to belligerents worldwide, and have altered the risks involved in peacekeeping operations. Civil society is having a progressively greater influence, through the major international non-governmental organisations (NGOs) invited to the conference table, the activities of vast worldwide press and audiovisual media groups, and the adoption of international legal standards to attempt to control the laws of armed conflict, including engaging the personal responsibility of the protagonists.

In these complex and changing conditions, decisions to go for the military option are increasingly motivated by the need to respond collectively to security questions which, for many states, are beyond the scope of resolution on a purely national basis. Such is the case, for example, with the stabilisation of a region after a conflict (e.g. Bosnia-Herzegovina, Kosovo) the protection of strategic supplies or threatened populations (the earthquake in Pakistan), security assistance to a country (Afghanistan) or the prevention of an internal crisis at a critical period (elections in the Democratic Republic of Congo).