Restructure society to value cooperatation over competition.

Break down unjustifiable hierarchies where possible and reasonable. The flatter the power structure is without sacrificing much in the way of efficiency, the better.

Rename to “armed conflict” or “special military operations”

How about massive free psychedelic doses?

This is something my old history teacher once mentioned: we have games like COD and other esports titles. Just have all conflicts resolved via virtual combat instead of in real world violence

Make everyone bulletproof and bombproof. If it is no longer possible to kill people using weapons of war, then there will no longer be a point to fighting the wars. Either that, or things will escalate to a point where it is no longer sustainable to fight wars that way, also solving it. Mind control, or gelatinising everyone into a singular hivemind is also an option.

Somewhat more realistically, I think that exchanges and the internet are the ways to go when it comes to ending wars. It's a lot harder to fight wars when you can empathise with the other side, and see them as your peers. It's one of the reasons why soldiers who took part in the Christmas Armistice were shuffled around, since they became friendly during the ceasefire, and would be less wanting to fire weapons on the friends that they made.

A lot of wars tend to centre around dehumnaising the other side, and treating them as the "enemy". Allowing people to co-operate and communicate mutually makes it a lot harder for that to take place, since you have experience with the "enemy", they're not that bad. You've even got friends there, and training a gun on them with the expectation and desire to turn them into a corpse is just not on.

The complete extinction of the human race

Kill all humans

Mass extinction event. Breed out aggression from our species we seem to be doing that but slowly. Space mining could potentially stop us from having war in Earth at least. AI takeover have everyone live on their own virtual reality paradise. For the most reasonable I think the best way to end wars is education and uplifting poverty nations not exploit them.

Edit: Or we can just be like Switzerland be a direct democracy, with how slow they decide things it will be highly unlikely to go to war at all.

Kill everyone. No people, no wars! Win/win in my book

Universal basic income, universal food and shelter and education.

Implantation of the post-scarcity society and the end of capitalism ez gg

Very easy. Global thermonuclear war. That should make sure that the remaining humans (if any) don't need to fight over resources for at least a few generations.

Abolish Money and increase global distribution of goods aka socialism.

There is no solution to that. It is a cold, hard reality of living on a planet with limited resources. We all might hate war (and for good reason, obviously), but it isn't like animals don't fight for territory either. Just happens that humans found a way to make it a few orders of magnitude more extreme.

When there's no war, people like Hitler won't have any opposition to their rise to power. Haiti never gains independence. We'd never have escaped feudalism.

Most wars are stupid bullshit and suck ass. The military, especially the US military, is the biggest waste of money ever. That doesn't mean that war isn't directly tied to lots of positive things like innovation. There's so much medical, industrial, and geographical knowledge we wouldn't have if it wasn't for some war, and that's just the tip of the iceberg. People's ideas will always conflict because different groups of people are going to have goals unique to them that clash with others

Now if you were to ask how to stop unnecessary wars, better more efficient rulers. Most of the people in power today are complete hacks. It's crazy

But I don't think we'll ever get rid of war and I don't know if that's necessarily that crazy? Ultimately it's apart of how we grow as societies

Make those who declare war to actually fight the war. Put the two countries president on each side of an arena with some swords to fight to death, the one who lives wins the war. I'd record and pay pee view or something and the money raised would pay for homes for the poor in each country

Education for everyone globally. War is, like all kinds of violence, an act or reaction of impotence (psychological term/not sexual).

It basically means nobody actually chooses to act violently or start wars. They do it because they believe consciously or subconsciously that they have no other options, because they can't think of any options.

This is always a wrong assumption, because there is always a better option. The difficult part is to getting people to understand their actual options. Education solves this.

There is this dystopia anime series called From the New World. The premise is a portion of humanity gained psychic power and led to the collapse of society because it's so powerful that order could not be enforced. Far into the future there's a cluster of communities that's able to exist, and the way they went about it was to genetically engineered humans so when they harm another human it triggers body functions that make it harder for them to breath and other things. Killing another human also kills the aggressor. It kind of works on the interpretative level so it's possible that using drones could still have an effect, probably.

Even in the story they explored ways to circumvent it though, but that's kind of a tangent.

Democracies rarely go to war with each other. Add mutual economical dependency to that and you have a strong base to avoid armed conflict. The EU is a good example for that.

Eradicate fear.

Fear of losing power. Fear of "them". Fear of going to hell because you didn't convert someone. Fear of lost resources.

It all boils down to fear. The problem is that fear is contagious. It's easier to convince someone to back your side if you make them afraid vs hopeful.

A single world spanning country.

If we don't kill ourselves off first it will probably happen eventually. Country sized used to be limited by things like communication latency, and the time it took to move forces around. Technology has shrunk the world so that those things no longer matter. The natural size limit on a country is almost certainly as large as the earth now.

It won't happen soon, cultures will take time to become similar enough to merge. Leadership structures take time to be absorbed into a greater one (EU style) or have to forcefully taken over (Chechnya style, thankfully very rare these days). But with no real impediment to countries growing larger, it will happen eventually. With no-one able to fund or support rebellion and modern technology making police actions extremely effective it may well last effectively forever.

Whether it's a democratic utopia, a dictatorial nightmare, or something in between for the common citizen is not yet defined. Either way, war, as in peer to peer conflict between sovereigns, will be over.

Let's first address all the "nature" and "biological" not-really-true claims.

The Batek people of Malaysia are so averse of killing other humans that refuse to do it even when threatened with slavery https://peacefulsocieties.uncg.edu/societies/batek/

So, war is cultural, not biological.

Second, why do we do war?

At first glance, is for scarce resources, for survival.

But look at the modern wars. Are they for survival? Are they for resources that we need to survive?
No they are not.
They are for power.

But whose power?
The power of those who actually have to fight and die?
Certainly not.

The power of the rulers, who are greedy for more power.

Most people need to be scared into going to war, need to be convinced that they are defending their families and their "people".

This is why rulers work very hard to build national identities, the good "us" vs the evil "them".

Here we need three things:

1. We need a culture that knows how to recognize those greedy for power, those with a desire to dominate, and see them as the threat to freedom that they are, ie some sort of https://en.wikipedia.org/wiki/Leveling_mechanism
   There are several cultures that do that, but it has to be a deliberate and conscious thing.

2. We need to rethink our identities, national and not, because those identities are used to define the "other" that is ok to harm and kill.
   A way to do this is to make sure that people who want to travel and visit other groups can do so easily: this will help the various groups understand and humanize each other.

3. We need a culture that stresses the importance of non-violent conflict resolution.
   Because if all you know is violence, then that's what you will use.

I mean, easier said than done of course, but I think that knowing the direction makes it easier to reach it.

For further reading on the subject, I would recommend Bob Altemeyer's "The Authoritarians" and Graeber & Wengrow's "The Dawn of Everything" from the top of my head.

Did you watch Shiny Happy People? Apparently Christian fundamentalists believe the world population can fit into Jacksonville, FL. There's the answer. Anyone who wants to start a war has to go live in Jacksonville. Build that wall!

Since you stipulated our species, to me, the answer is an external threat to the whole. Aliens, higher or lower dimensional creatures, cryptids, flame unicorns sharting lava, even angels or demons if we want to get real wild.

Even just the threat of an existential terror such as these and probably a lot I missed, (feel free to add to the list! Feed me your existential threats!) has the potential to bring the species together to fight on a larger scale.

However this doesn't eliminate war just moves the focus. So I'm not sure if I've answered your question or not but I had fun doing it!

End capitalism (& the nation state/state in general)

Put all leaders together in a hall with good music and cozy interior and give everyone MDMA.

Kill every human being. No people no war.

Economic democracy; if money and resources cause wars then why not let everyone have control? I will probably hear the human nature stuff but being social is just as if not more important than hurting your species/society.

The question is ill-posed.

War is just a tool, a collective act of violence that a group of people do against another in order to obtain a result. It's always sad and it's always bring sufference, but one could say sometimes it's necessary. If you cancel war from the world witouth changin anything else, you will ends up probably damagin more the one with actually less power, since violence is usually the last resort in order to confront someone that hold political, economical and soft power upon you.

If you wanted to ask how we go to a situation when wars are not necessary and they are actually the less convenient and effective way to obtain collective or personal results, so that we ends up with no actual war are started, here's my answer. We need to build a system that minimize close to zero the difference in power (every kind of power) between people, and we need to build an efficient an relieble system to intermediate and resolve the inevitable conflict between people and groups.

Benevolent global AI dictator. These never go wrong in sci-fi after all.

(has to be true AI like Daneel Olivaw, not this fake LLM crap though)

Equal distribution of wealth and power, along with trying to create universal standards of communication (I.E. speaking reading and writing) would help probably.

Plus universal access to education and birth control. And ENFORCING equality by making sure there is no such thing as inherited wealth. Each new generation would have to start form the same point. I know it might seem a little extreme, but I think it's the only way to prevent oligarchies, monarchies, and huge concentrations of power that distort society from forming.

Plus, guaranteed clean food, water, housing, and basic healthcare for all. Get rid of the reasons for conflict, and make sure those who want to start conflicts can't ever mass enough power to start wars and we won't have them. A lot harder to justify fighting when you personally have to do it all yourself because you can't order others to just do it for you.

Nuclear deterrent. If that fails, nuclear annihilation. Either way, there will be no more wars.

People say violence is never an option, but violence is always the last option. We can try arguing, debating, convincing, compromising, making concessions, begging, bartering, betting, but at the end of the list is the threat of violence followed by actual violence.

If we want to reduce violence, we need to find a way to settle disagreement somewhere before violence. Otherwise, all disagreements just get closer and closer in a game of brinksmenship. Those who blink first lose.

Kill every human, or all but one. As long as there’s at least two people, there will be conflict.

Simple. We make war illegal.

Like others said, struggle is in human nature. But it is possible to shift it to other domains: art, science, exploration. To prevent this stuggle spill back into physical violence, there should be broad consensus on basic rules, effectively enforced.

So I'd say, build this consensus, which will probably need to rely on abundant renewable enengy, some form of UBI, equality, and stronger international institutions, but will not spotaneously evolve towards unsupportable preferences of some groups.

The only way to permanently end war is universal omnicide.

Put everyone in a Matrix and let the A.I. lead the humanity

It's (theoretically) impossible -- you can't break someone's (ignorant and established) will/ideas/plans with words alone or treats. Most world leaders are megalomaniacs by heart, i.e they won't stop until they are done with what they want.

It would take way more but the first step it would be to remove religions. And not only because most are not peaceful in principle but also because some religions see others as a target. Even small difference in beliefs could spark a vicious and long standing conflic, like Catholics Vs protestants.

Put the ones in charge to the front line.

Put everyone in a time-out until they can play nicely with the other children (because let's face it, a lot of them are acting like children)

Easy enough, we just build a jail so big that we can fit the entire world inside of it, boom no more crime.

Humans are ultimately animals. We strive for dominance on an individual and societal level. We can run societies in a way that helps to minimize violent conflict but I don't think you can ever eliminate it. Not while still being what we know as human.

Bonobo way

Colonizing space

An unfortunate combination of somehow achieving a post-scarcity, non-capitalist society with robust resource and population control.

But people are greedy and want "freedoms" that run counter to this.

The only way to end all wars is for all people to fully control the instinct of domination with rational mind. It's all about education and self-awareness. Making people rational creatures

You'll have to find a way to eliminate greed

Edit: or no people so you have nobody to start wars

I think the solution is to have enough renewable energy for all of humanity.

Impossible. There is 1-5% of the population who are born anti-social. It's very difficult to socialise them, and some never do. They are vastly overrepresented in prisons. These people sometimes get into positions of power. Particularly in societies which value authoritarianism, like Russia and China. This cannot be helped. Instead, we must mitigate the effects of their reach. NATO, for example, is an excellent way to stymy these dictators.

As long, there are rankings in society, money, and power and human emotions – conflict will never end.

Make the old men fight each other and soilder just refusing to follow orders that seem stupid

I think it would be bad to end all wars.
War sucks, no doubt. But think about this: throughout history, fighting has led to larger, organized societies that decrease violent deaths. These societies also improve living standards and boost our wealth. So, war makes us safer and richer.

WashingtonPost - In the long run, wars make us safer and richer (April 25, 2014)

use nuclear bombs on everyone who doesn't comply

set aside a space for any country that wants to war, they have to deploy troops/etc there & fight there. anything goes, any atrocity or tech someone wants to use. but everyone is always watching - cameras and sensors everywhere and 24x7x365 coverage on a freely accessible dedicated stream/tv channel paid for by taxes levied against the populace of any country that chooses to war in that space.

it'd be the most highly watched stream ever, forever.

Give every man a nuke

Get rid of religion

Democracy and the rule of law. Sounds banal but it's the best shot we have. People crave power. People who have power want more of it, which is the underlying cause of a lot of wars. People who have power will do absolutely everything to keep it, including starting or prolonging wars.

Therefore people who want power - regardless of the system of government - are inherently unsuited to use it responsibly. The solution? Give power only on a strictly time limited basis and within a framework of transparency and control. If you misuse the power lent to you, you will be held responsible.

This won't prevent shitty governments from happening, but at least it provides a way to get rid of said shitty governments. So, far from a perfect solution but the only realistic one.

Make tea

Send everyone in charge to an Enya concert. "We can sail, we can sail, With the Orinoco flow..."

A death match between the presidents / prime ministers of the rival countries. The country of the winner of that match will win the war, and the country of the loser has to deal with the following consequences.

Well effectively, it would entail an all-encompassing global spying machine that gathers all data possible, and imprisons anyone who deviates from the expected baseline. (Wouldn’t end well for me either.) You have to remove most individuality to remove reasons for fighting. And even if you imprison 999 false leads to capture just one instigator, that’s the only way to ‘guarantee’ a fairly high level of security.

So what I’d say we need is 1984 or Мы levels of oversight to have any chance of curtailing conflict for good.

EDIT: oh, and re-education. Lots and lots of re-education.

That's another rule. No wishes containing the word 'all'. Guaranteed ironic consequences.

I don't think anyone's going to miss wars.

Star Wars, Thumb wars, wow, Storage Wars!

No hands for anyone. Possibly no feet too. Only the cooperative will survive.

Replace war with gaming competitions, No Game No life Style.

Small disputes are solved with simple game likes chess, major disputes/ultimatums that would otherwise result in war are played with war-equivalent games that would mobilize the entire nation, say an all-out drone battle. Refusing to honour the outcome results in North Korea styled sanctions.

crazy enough it might just work!

Post scarcity, de-population, or colonization of new worlds.

Humans need to evolve to a state where love, compassion and being helpful to others is ingrained. At the moment we're just clever beasts.

Sadly though, I don't think we have enough time.

Peace, by force

Humans are gonna human unfortunately. Biologically I’m not convinced we are capable of eliminating war because humans are competitive by nature. To the point that there will always be one group or another trying to force its ideals onto another.

I’ve often thought about “what if we could snap our fingers and every weapon beyond that of a spear (technologically) was vanished, and any/every attempt to fashion something deadlier would fail/poof out of existence as well.”

That might stave off large scale war but there would still be tribal warring on a smaller scale I fear. Plus a ton of other issues that would arise from suddenly having no guns/missiles/projectiles/etc.

People not joining armies one by one

Just hit all the buttons; it will sort itself back to a natural balance. Then eventually we might have a button to hit again.

Forbid them

If you see war as a struggle to get access to scarce resources and if you notice that currently humankind is depleting most of the available resources then you might come to the conclusion that if in the future we will not need to go to war something terrible must have happened. Are you sure about the future you want?

Establish a global trade network in a way that everyone is completely dependent on everyone else.

this is a bit grim but global-wide information control that shreds any information which will help the growth of the idea of overly patriotic but less enough to not kill the domestic culture (but i think, not necessarily always telling the truth). that will also promote the sense of global village and transnationalism. and relocate the idea of war to other rivalries like on sports or something, idk.

basically limit the free will without showing it. I can't think if it's gonna happen or this even possible.

Build a truly massive nuke, threaten every single country that you will wipe it from the planet if they even think about invading another. Make sure to follow through on that promise on the slightest indication, just so everyone knows you're not joking. Ideally, you would hand this over to an AI that keeps score of each country's behavior and prunes the ones that don't behave without any moral concerns.

Problem with that approach is, that you would probably be out of nukes by noon of day one.

We need a global nation to represent the millions that live in a culture society and economy built on the Internet habilty to interact with everyone else in this planet. With structure and representation relative to the economic and cultural power they hold in the global political scenario. Not a utopian global nation for everyone, just one among the others.

Massive doses off mdma for everyone. All the time.