The coincidence of Russia-Ukraine war, in Europe, and Israel-Hamas war, in the Middle East, reawakened debates about the ultimate origins of war. The never-resolved enquiries about the primary reasons to reiterate lethal inter-group confrontation renewed old questioning. Despite the legacy of knowledge from paleontological, archaeological, and reliable historical chronicles or from the most cogent strategic, economic, or philosophical analyses, the remote roots of the tendency to repeat wars are devoid of solid explanations. This article sustains that the paths to unravel the essential answers to this question must be sought at the fertile crossroads of scientific disciplines that deal with the biology of human competitive coalitions. An outline of the most relevant psychobiological factors unveiled so far is presented here. This review exemplifies how to combine the role of these primary factors with technical analyses of current wars, both to improve the understanding of ongoing conflicts and open research endeavors oriented to strengthen initiatives dedicated to maintaining peace.