We do have the capacity to annihilate each other ... however I disagree we have always done it.  some cultures have done it, others found ways of forming functioning confederacies between disparate peoples ... wouldn't it be awesome if - given our capacity to self-destruct in a few ways in our historical moment - nuclear and environmental devastation but two of them ... that we enter into authentic dialogue with all cultures on a plane of mutual respect.  

for example - the Incas had roads every bit as awesome as the Romans with very sophisticated agricultural practices from which we could learn so much.  Their roads were to ensure all within the confederacy had food should a crop fail in one part but not in another.  A huge mistake of the last Inca was trying to make the Christian Europeans go away by giving them all the gold for which they asked.

He couldn't understand their fascination with it as they could neither eat nor drink it.  I wonder which social order pleased the divine/