I'm not sure how you can say this with such certainty. We're less than two generations out from the last "world war", we arguably have other countries and regions that would be involved in the next world war, and resources continue to get more scarce without any sign that the globe (and the developed, industrialized countries) have learned to "share"
There are no long-term resource worries in the developed world.
This goes against the folk-wisdom and fear-mongering present in a lot of popular culture, but it isn't true.
In the developed world fertility rates are below unity. Oil, at it's recent peak was competitive with solar. Resources aren't going to run out, the prices are just going to change – some resources will have to be more aggressively recycled, others will have to be replaced. Billionaires are thinking about asteroid mining. Nobody in the developed world is going to start wars over shortages.
There's a huge amount of arable land which is either unused or grown with only the most primitive techniques. Modern agriculture requires a fairly advanced economy, but it is orders of magnitude more productive.
"Resources are scarce" is a very believable lie, and it's easy to misuse statistics to prove it's true.
Remember "peak oil"? It wasn't true before and now nobody really cares that much.
The best car in the world is American and electric. In a few years they'll be selling one suitable for the middle class. We don't _need_ oil for energy, but we're going to use it until the economies of developing technology overtake the increasingly more costly fossil fuels.
In a generation or two people will stop fearing nuclear, and fusion will become economically viable.
I'm sure during the Pax Romana a lot of people felt the same, or even after the First world war. After the plagues in the middle ages resources were abundant for everybody, even peasants..
we are no different than then, sure we think nowadays technology seems able to change everything, but before it was the same. Humans have always been innovating and increasing efficiency, yet they have always been fighting.
Sander van der Leeuw (University of Arizona/Santa Fe Institute) takes the view that we've gotten into our current predicament through technology:
"Most people in both politics and general society think that we need to innovate our way out of the sustainability problems that we're having. What we forget in saying this is that we innovated our way into this problem in the first place."
The point I'm trying to make is that these problems are already solved. That is, when the pressure is high enough (and it's been shown that it won't need to be that high) it's clear that there are viable solutions to our resource problems.
I'm pretty sure the sentiment that a large war has been made impossible, either through technology or politics or both, pre-dates the first World War. Certainly after the first World War, it was thought that war had thus become so horrible that it would never happen like that again.
MAD has worked pretty well so far. It seems almost certain that there would have been a massive third World War by now if nuclear weapons hadn't been invented. But that doesn't mean it can't ever happen, especially since MAD is a lot harder to work with in a multi-polar world (there are currently nine countries with nuclear weapons).
