However, humans are a single species- interspecies 'war' is to determine which one dies off. All human war is stupid in principle- at least, every beginning of a war (WW2 was necessary to enter once Hitler started it, etc.). Rather than punishing weakness, we should try to help the weak. Most war technology nowadays is a waste of time, as it doesn't help humanity advance, but rather decline.
I don't know if you'd like to see what the world would look like if war didn't happen.
My guess is that we probably wouldn't have evolved this level of intelligence.
We didn't need this intelligence to feed ourselves or compete with other species... chimps are considerably smarter then most other animals and do very well for themselves... when humans don't kill them.
Our brains are likely what they are because they were needed to compete with other humans or to compete with other hominids that were likewise smarter then chimps. It was a intelligence arms race.
Humans won.
Consider further that war weeds out stagnant cultures that aren't developing, weeds cultures that fail any critical objective... something as simple as breeding at an acceptable rate is an example... if your group breeds half as fast as another group you're in competition with then you'll probably lose.
This is why for example I think most societies in the past were repressive of woman. Repressed woman tend to breed more often. Which means your society has a larger population.
The first ones would have left the trees, then showed the others what a sweet life it was. When people cooperate, better results are achieved than when resources are wasted on wars over greed.
That's not how nature works. You're not just taking away war, you're adding something that doesn't exist.
War, as terrible as it is... is probably good for us. The only sad thing is really that we can't practice war anymore except against pissant little countries that don't really pose a threat if we went all out.
War forces your culture to stay strong, evolve, keep an eye out for the enemy, or die/become conquered/be enslaved/be raped.
Without war, we would probably have cured cancer and poverty by now- possibly even spread human rights universally.
Unlikely, I'll point out to you that expertise in medicine and military expertise often went hand in hand. The romans for example were excellent doctors for their time. And the civil war in the US and WW1 in europe did much to improve medical science.
Now, both are products of science that we would have arrived at eventually, but I don't know if you can say we would have developed science were it not for real threat of conquest.
It is no mistake that chemistry was most interested in making gold (alchemy) and then immediately became interested in explosives and propellants when it became known that such things existed.
Consider rocketry... most of that came from missile research.
Even astronomy had military applications as it allowed for navigation.
War in itself is not the most negative invention of man- that would be hate, which starts most wars- but it is the most painful symptom of the disease.
No, I think it's more greed. Greed for power, greed for money, greed for honor, greed for glory.
When you have set your mind to kill something you'll invent reasons for it... oh, I hate them... oh my god tells me to... whatever.
