“War is the father of us all, King of all. Some it makes Gods, some it makes men, some it makes slaves, some free.” ~ Heraclitus.
"Homer was wrong in saying, “Would that strife might perish from among gods and humans.” For if that were to occur, all things would cease to exist." ~ Heraclitus.
Heraclitus is taking a logical and realist view of mankind. History tells us that wars and strife between civilizations is the key pillar of progress (innovation, discovery, creativity, invention, and the pursuit of happiness). Without battling the old establishment, you cannot create a new world. It is on the debris of the old civilization that the edifice of a new civilization is built. It needs a supernova, the most destructive event in the universe, to create new stars and planets.
The people who annihilate a civilization are often the ones who lay the foundation of a new civilization. Not all new civilizations are better than the ones that have been annihilated—in every evolution there are some dead-ends.