All matters of art and sport found geneses in the emergence of
discretionary time.   Those not artistically inclined had the time to ponder
themes related to disproportionate human significance. All matters of war
and religion found geneses in the emergence of discretionary time.

As an instinctual response it would appear war is waged for the purpose of
reinstalling relative equilibrium among competing forces...  To conquer...To
emulsify.  

The beneficial outcomes of violent wars are mostly imagined and
accomplished at the expense of overcorrection and the threat of
extinction.  

Any violent war perceived as resolved continues to reverberate for
generations forward while simultaneously distorting interpretations of
both, past events relevant to cause.  There is a disconnect relative to
comprehending connection to the present, obscuring visible connection to
the actions of prevention relevant the future.
The existence of war wrecks havoc with the
notion of evolution.  At first glance there
appears nothing about war that aligns with the
laws of nature.  
An adaptation morphs to a collective belief that there are times war can be
viewed as legitimate and/or fully justified if for no other reason it has
never not existed in our lifetime or any known prior- and we are surely
more enlightened then any who have come before!
Viewed through the lens of evolution such
violence is baffling and fully contradictory to
the notion of an evolving species- once taking
life only for the purpose of physical sustenance.
The Individual struggles to understand the existence of war only to find
the pursuit ultimately in vain.  The end results are certainly tangible but
the sequence prior eludes collective comprehension.   As a consequence
the Individual borrows the balancing features from other realms in an
attempt to explain.
It seems that War viewed from any frame has no force or entity to function
as the polar opposite antithesis.  Absent lasting fix humans do what
humans do best...Adapt.  It is an adaptation acquiescing to the perception
war is a reality affixed to any given society.  
ANYWAY...

Early humans dedicated most of their energy to the basics of sustenance;
they had neither the time nor the tools to create many enemies of same
specie. As the ability to better cultivate resources advanced, humans
began to realize an expansion of time to pursue less-critical activities.  
At what stage did humanity acquire the ability to kill like kind for no
discernable higher purpose?  There truly exists a 'missing link'.
WAR!

War throughout the ages

idle hands

Those not artistically inclined had the time to ponder themes related to disproportionate human significance. All matters of war and religion found geneses in the emergence of discretionary time.