No Stupid Questions

Abolish Money and increase global distribution of goods aka socialism.

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!

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

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

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.

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?

Put the ones in charge to the front line.

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.

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.

Create an Artificial General Intelligence with the sole purpose of satisfying people's values through friendship and ponies.

People not joining armies one by one

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

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.

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

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.

The only way to permanently end war is universal omnicide.

Simple. We make war illegal.

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.

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.

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

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.

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)