..." Even if we one day achieve world peace, would we be able to sustain it?"...
For the sake of mankind, I certainly hope not...
The idea that human conflict is intrinsically linked to the overall advancement of mankind may seem, on its face, an counterintuitive assertion.
However, if you consider just how much our endeavors in warfare have advanced medical technologies ALONE then one can field a sound argument that, with the thousands of people that benefit from war-born medical advances EVERY SINGLE DAY, - war has been quite beneficial to mankind; the math is simple.
That said, - many people will still condemn acts of war and, although I understand the motives behind such condemnations, - they are not at all based in sound reason. Rather, they are based upon emotions which have been conditioned by adherence to a moral construct, - and the facets of morality are a matter of PERCEPTION.
As for the 'negative effects' of world peace:
As I see it, - in times of 'peace' we are allowed to be somewhat more selective in how we choose to live our lives; more 'economical' in how we expend our energies within that which we have defined as a 'way of life'; a life of relative calm and patience.
With 'war', however, - when that calm 'way of life' we have created for ourselves is threatened, - we are then forced out of our more leisurely activities so as to fight for and protect our very 'way of life', -and those who fight without zeal, without determination, without 'passion',... will either wind up in chains, - or on a Butcher's Bill.
Without this 'passion', - I feel the most negative impact of perpetual world peace would be:
APATHY, - the most inhumane of all human conditions.
In his book THUS SPOKE ZARATHUSTRA, Nietzsche wrote:
---..." You should love peace as a means to new wars. And the short peace more than the long."...
" War and courage have done more great things than charity. Not your pity but your bravery has saved the unfortunate up to now."...---
I'll buy that......
Saint Christopher Walken
Patron St. of Humanity Via Human Conflict