New developments in weapon systems during the 1950s and early 1960s created a situation that was most dangerous, and even conducive to accidental war.
Often, the pretexts for starting a war are not real shortages of land, food or fuel, but rather perceptions - like fear, honor and perceived self-interest.
Well for one, the 13th amendment to the constitution of the US which abolished slavery - did not abolish slavery for those convicted of a crime.