In 1945, the preamble of the United Nations (UN) Charter, while emphasizing the determination “to save future generations from the scourge of war,”1 established a clear dichotomy between good-represented by peace-and evil, represented by war. In fact, with the Charter, war definitively gained a negative connotation. War was to be banned and the use of force between states forbidden, except in very special situations. Peacekeeping operations, which in their original formulation were

not intended to use force, were conceived as a formula to assist in negotiating solutions for conflicts and avoiding wars.2 The key principles of peacekeeping were established during this period: impartiality, consent, and non-use of force except in self-defense. These principles are so important for the construction of peacekeeping that some authors refer to them as the “Holy Trinity” of peacekeeping.3 The discourse of the peacekeeping formula for international intervention was, from the very beginning, clearly dichotomous in relation to war: use of force non-use of force; political non-political; dissent consent, among others. Nevertheless, this attempt to avoid wars

between states ended up creating, especially with the emergence of more robust peacekeeping-and, later during the 1990s, humanitarian interventions4-the conditions of possibility for the use of force on behalf of the international community.5