It is well known that huge advances in technology and sometimes in science occur during wars. Inventiveness takes off because a war brings about a whole different feeling in society. Instead of people vying for personal space they are all pulling in the same direction, and governments eager to remain viable give money to every idea that comes along. In fact it is during war that ideas become the currency.
This is wholly in accord with what we know of nature as evolution favours adaptations in animals that enable them to survive and breed the next generation and eliminates adaptations that leave the animal more vulnerable to attack and disease. This is because nature herself sets us challenges on a daily basis, from the single cell to the complex animal.
There are those who say there is no reason for this and others who look for reasons because we are geared up to find answers to any question that enters our heads. Since evolution in the universe is a continuous process it can hardly be said we have sufficient reasons to create a theory as to why antagonists vie for supremacy in the natural world over and above any immediate considerations of survival.
But since the universe is a complex, single system I wouldn’t mind betting there are such reasons and we will find them out one day.