This example has little to do with assumptions or emotional appeals. It is how humans interact. History is absolutely full of examples of groups unwilling to share their natural resources and many people died in wars fought over resources.
If this group B cannot be forced into cooperation then what use do your DRO's have? Exactly, zero.
Group A will start a war for water because they have no future anyway. Instead of stabilizing this plateau of trust you put societies in a ring and go "Fight!". Sure, a winner will emerge, but at what cost? And who would be willing to pay this cost?
Of course this is how some humans interact, but we still live in a pre-civil society. I'm not going to pretend I know into detail how a real free and civil society should look. And that is exactly the point: Neither do you. If you did, you should be made dictator of the world and I'd probably support you
The best way to create a civil society in my opinion would be to let the market (i.e. all of us) find the solutions to complex problems. That's what free markets do best. The market can supply defense agencies, law enforcement, etc. just like it already supplies basic necessities today like food, shelter, clothing, insurance, etc.
It's sad to have to explain that we, humans, are not capable of what we think is good behaviour.
The point is not that that is how some humans act but that there always will be people that will act like that.
We have a lot of built in biological systems that take precedence over reason and we cannot allways control all of these systems.
I may not be able to predict the exact future but i can sure tell you what will motivate people, even in the future.
I can also tell you that, for instance, greed is one of those built in systems.
Greed evolved because apparently it alowed humans to somehow survive better in the past. The greedy monkeys survived and it is us.
So
any system you propose will need to be able to cope with these human factors or else it has failed before you can even implement it.
The error you make is thinking that humans are these mythycal rational beings. We are not, we are pretty amazingly irrational overall and its amazing we survived so long. My guess is that overall a general concensus of rationality started to form but it not something that supports itself automatically. It needs to be cultivated. And then it turns out that not everyone agrees so the potential of education has its limits as well. You can tell people what is best for them but not everyone will agree.
The point about violence is that it has been proven to be needed to organize large groups of people into something we call a society.
The less precense the state has the more violence it needs to excert to keep parasites in society low. This becomes clear from statistics on criminal activity. It is a fact that if you remove state organized control you get an increase in internal conflicts. People start strealing because they think (rightfully) that they can get away with it. The only known solution against this internal combustion is the threat of violence. That is the only thing thiefs will understand.
But this, of course, brings in a new problem.
Who is controling the controler.
And i think this is what we need to address.
It is not that there is no need for control overall, its that this control is taking on forms that are not in the best interests of society.
It is increasingly being abused to protect the structure of corporate entities instead of protecting the structure of society itself.
So even the free market entities will destroy themselfs.
If you have two competing security firms then between them the easiest way to compete is to make the other organization smaller. It is more efficent to just kill off the competition than putting resources in competing on product quality.
A bullet is cheaper than changing your ways so
without a bigger force there is noone to stop them from taking the easy (and economic!) path.
So there will be a natural tendency of hostility between such groups. There will be a power struggle in no time. When such a group also starts spewing political rhetoric they can even get support from society and you have yourself a freaking monster.
And again, this has played out many times in different versions for different reasons.
The only conclusion you can take from this is that humans are not capable of sustaining their ideals and need help to at least keep society pointed towards these ideals. Without this help people will fork out each others eyes over the most stupid shit.
Just take a look at countries where family feuds are still accepted. People do these type of stupid shit. It is in our genes to just take and not think about giving. Giving needs to be asured by the largest power structures to make society work because people fail to do it by themselfs which invariably leads to conflict. The role of the large power structures is to prevent internal conflict.
But it is also true that by suppressing conflict this structure also can suppress usefull dynamics (and even some conflict can be usefull as long as it doesnt escalate too much) and that leads to oppression.
So as i tried to explain before, it is all about balance. And to be able to have this balance the big structure needs to be controled by society as well. Just not too much by group think because that brings out our non-rational part.
But for the sake of argument I'll bite.
You say group B has plenty of water. What is the reason that these people don't want to give up their surplus of water? If they have plenty, wouldn't it be in their own economical interest to trade with group A instead of outlawing themselves from the rest of the world? Because surely the rest of the world would take notice and refuse to deal with these people. I think it would not be in their own interest to refuse to trade if they had such a rare and valuable commodity.
Primary reason is that group A has nothing of economic value for group B. And they have a different religion and the gods of group B forbid them to trade with groups that eat purple things and it happens to be that the main food source of group A is a small purple cactus fruit. How convenient. But have you never heared the story that people who eat pork are unclean?
And altho they have enough water they know that their supply can end some day.
They are just greedy bastards and they figure its better for
them to survive twice as long instead of sharing but having half as much water. Even taking the risk of not having enough water is enough to not share with the infidels.
They are self sustaining anyway so they don't need the broken economy of the waterless state.
Meanwhile another group somewhere has oil but no water.
Now group B is interested because oil is cool.
They make a deal with this group to exchange water for oil.
But. Group A still doesn't get anything and even worse, because of the water shortage they are unable to produce anything of value.
Do you think group B cares? Of course not!
They are HAPPY. If group A dies out it means group B has become stronger and it is only natural because group B is the chosen group, at least that is what the shaman said last week.
What they don't realize, of course, is that by making themselfs stronger and larger they put a bigger strain on their natural resource and in the end this leads to the same conflict as between group A and B but then fully within group B.
You get classes of people controling the water and classes of people being deprived of it. This will then lead to civil war etc etc etc. Like i said, history is full of these type of interactions (group X being selfish about a resource or just generally selfrighteous which leads them to think they are the only group that should survive and makes them act on that belief). Power corrupts.
As i said, most wars are about resources. This has always been so, no matter the explanation. Taking land means you take over the resources of someone else.
This is what humans instinctively do unless there is a
stronger force
above them stopping them from taking over.
It is what out ambitions lead us to and it cannot be fantasized away.
This is exactly why we are in this tangled mess of global relations and it is not something that you can solve by resetting the system.
By reseting the system you will force all these relations to become re-evaluated by everyone. This means massive war on all sides and total chaos. Noone will be sure anymore about whether they can assure enough resources for the future of their population (you need to think ahead
many years to have a steady supply of resources to survive as a civilization) and the only way to be sure is to take it and sit on it.
Groups of people united under whatever cause tend to become pretty egotistical when pushed.
And you want these groups to compete. I don't think that is a good idea.
So in short, your solution to have a "civil" society is to use violently enforced political structures? Your solution is to use force to have group B to give up the resource? In the end you'd have to be willing to kill to enforce that. I don't see how it is a valid argument to use force, coercion and violence to get what you want in any non-theoretical scenario.
I propose that the threat of violence is the only way to ensure the cohesion of political structure.
One of the problems is that if you look realy close every single person on earth has a different sets of ideal.
So in the end, if you want a perfect society where everyone can do what they want you will get conflicts.
We can then write laws that prefer one subset of ideals over another but you can do that ad nauseum until you discover that everyone needs their own government to represent them fully.
Coflicts between people is natural and you cannot let all conflicts simply play out because humans let this escalate into fights to the death. The only mechanism know that can prevent this is the threat of a bigger force telling the parties to stop fighting or else.
Adults are actually big children. We have realized this and recognized that the world needs parents of some sort.
Problem is, our parents are becoming abusive again.
Secondly, can you think of any resource in real life, that is
1) as rare as you described
2) necessary for life
3) can be held hostage by one group of people
4) cannot be engineered around (drinkable water can be created in many other ways)
Water is scarce in large parts of the world. Those parts are often in wars with goups that have the water.
Food is scarce in large parts of the world. Those parts are often in wars with groups that have the food.
Energy is scarce in many parts of the world. Those parts are often in wars with groups that have the energy.
Land (for human use) is scarce in most parts of the world. A lot of wars have been fought over land.
In fact land is such a good general resource (it often has the potential to bring both food and water, both are needed for survival at the most basic level) that it touches humans on a personal level. Having and protecting a piece of land is seen as the penultimate token of achievement in many societies. Land allows the owner to survive. This scales from the individual level all the way to global-ish levels as do the conflicts over land.
What would happen if the arab countries would increase oil price by 10x?
I'll tell you what will happen. The west will start a war against them to ensure their oil supply.
The war in Irak was because Saddam decided he doesnt want to sell his oil into the dollar economy.
Did you notice how the second Irak war was glued to the Afghan war? Like, "Ow, and we did Irak too".
It was a powerfull signal to the oil producing countries to STFU and start pumping.
This is how stuff works geopolitically and no construction of plan will change these kinds of relations.
There will always be people living nearer resources than others (we cannot all live in saudi arabia) and these people will have the position to control the access other groups will have to this resource.
What if group A was 20x larger than groupb B and the water could not ever be enough to support both groups?
Group B will commit suicide along with group A if they share this resource.
And this can even play out like the story of the cricket and the ant. Group X saves a resource (like food) for late and group Y does not. When the bad years come group X will have food but group Y does not. Group Y now has a very had incentive (survival) to rob group X of their food.
If you have no plan to solve these disputes then your plan will not solve anything and
will destroy everything as it will force an evaluation. It will trigger a global game of dominoes and the whole structure we have now will break. If group X doesnt get its oil from group Y it cannot produce the goods that are needed for the survival of group Z and group W that does a lot of transporting of goods will lose out on the action and perish as well. All infrastructure, all production, all food suplies, all energy supplies, all medical care etc,etc, etc. Everything will stop functioning while the dominoes fall into their new stable point. By the time we manage to get things going again most people will be without jobs and without food.
You'd realy have to hate the whole of humanity to give up on what we achieved now to go through the brutal process that will surely follow a sudden re-evaluation of relations in the world.