This paper offers a perspective on the relationship between Non-Governmental Organisations (NGOs) and the military in modern complex Peace Operations, whether or not mandated by the United Nations (UN). The relationship between the two has often been marked by acrimony and mutual exchange of accusations for the claimed lack of success for advancing a joint agenda nested within the Comprehensive Approach. It suggests that the need for cooperation and mutually agreeable objectives between both sets of actors has never been more pressing. The paper further argues that much of this ‘Collision of Mindsets’ is predicated on fundamental ‘fault lines’ of cultural differences accentuated by a lack of understanding or unwillingness to see the others perspective, and that, correspondingly, each needs to actively embrace an agreed Modus Vivendi so both can share and cooperate on the stage of modern crisis management/humanitarian scenarios.