Is it plausible to have a warring civilization on a fertile land neighbouring a peaceful civilization on arid terrain?

Question

I remember watching an episode of a documentary, named "Big History", that posited a general rule:

1. Humans living on fertile lands have more resources to develop a sedentary nature, via agriculture. Stability leads to cities, from which springs culture until eventually a civilization is born.
2. Humans living in more barren lands, especially cold ones, don't have access to these resources. They can not live in higly populated centers and must remain nomadic to find food and shelter. They become rugged and tribal. If they find one of the "fertile civilizations", they will feel tempted to plunder their resources, so they will develop a more warring nature. The example that was given as a paradigm for this was that of the mongols.

Now, this doesn't mean that the "fertile civs" can't specialize in warfare, but civilization will certainly play a moderating role, so they will be less aggressive than their barbarian counterparts.

Or so it was postulated on that documentary. At the time, it seemed reasonable. But I admit that there may not be so truthful.

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So, my world turns this upside down. I have a warring, tribal, nomadic civ that used its military might to cast a peaceful, cultured and sedentary civ out of the fertile lands and into the wastelands.

Now, how do these civs retain their characteristics, even though they are now living in environments that discourage said characteristics? Can the warring civ remain tribal and nomadic, even though they are living on lands that they can farm? Can the other civ remain peaceful and resist the temptation to regain their land again by force, satisfied with making ends meet in fertile pockets in the wasteland and trading between them?

To allow this to happen, I'm trying to rely on cultural, philosophical and religious ideas that shape the collective psyche of these civs and that prevent them from mutating into one another. But will it suffice? Why or why not?

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Note: For the purpose of this question, let's say that the technological level of these civs is equivalent to that of the ancient Roman Empire and the surrounding barbarians (I'm talking about tech, not culture)

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EDIT: Since it seems that I'm being misunderstood, let me clear this up. I'm not asking how the civilizations will get on that specific situation. I'm not asking how those civilizations would work. I'm asking if it is possible for them to retain their aggressiveness (or lack thereof) after being sent into environments that seem to promote the opposite behaviors. It's only one, very specific question

Answer 1

Not likely, the Mongolians found this out the hard way

Tl;dr

Humans, and organisms in general, will adapt to whatever the present conditions are. We see this along all time scales. On shorter scales, human muscle and bone will adapt to weight lifting by becoming stronger. On longer scales, human culture adapts to the environment as seen in the middle eastern Bedouin who culturally optimize for mobility so as to be able to take advantage of new opportunities.

Note also, that there is a cost for maintaining a high state of strength/readiness. This cost goes up as strength increases. Thus, an organism/human will only maintain a state of strength sufficient for the circumstances, and not more than that. In the case of the Bedouin, their optimization for mobility comes at the cost of being able to develop cities for commerce and wealth.

There are also examples from the US Vietnam war where soldiers returning from "the boonies" would be described as "off", "weird". It would take them a few days/weeks to calm back down.

A Classic Example of Going Soft

Genghis Khan, and the Mongols who followed him, had a reputation for being completely insane by anyone else's standards. They lived on mare's milk and horse blood. They wore clothes till the cloth literally fell off their bodies. Their mode of warfare was absolutely brutal, slaughtering people who put any resistance and slaughtering the people who didn't resist at all (sometimes). The steepe are an incredibly inhospitable place but the Mongols thrived there.

The Mongols liked stuff (doesn't everyone?). Their nearest neighbors were the Chinese who had tons of really nice stuff. Because the Chinese had all that nice stuff, they also developed heavily defended cities to make sure they kept it. After smashing into those fortifications a few times, the Mongols adapted to the new obstacles and became terrifyingly good at siege warfare. They got good enough that they conquered large swaths of Chinese territory and all the wonderful Chinese fine things.

Between Genghis Khan's death in 1227 and Kublai's announcement of the Yuan dynasty in 1271 (just 44 years), the Mongols got used to all the nice stuff. While they were still astonishingly good warriors, they had lost that special something that made them truly terrifying.

Despite an immensely strong cultural idea that the Mongols were destined to rule the entire earth, that ideal wasn't strong enough to ensure that the individual Mongol warrior stayed at super-high fitness levels. The Mongols were also extremely tolerant of other religions, going so far as to sponsor the occasional sect. Originally, the Mongols were shamanists.

Strengthened by Religion?

Personally, I don't think that religion or cultural ideals alone would be enough to permanently prevent the hardened warriors from softening in the presence of nice stuff. Those religious ideals might forestall the softening but not prevent it. The only way to get and keep warriors hardened is to put them back in the circumstances that originally made them hard. For the Mongols, that was a tour of duty back out on the steepe.

Go listen to Hardcore History

I know I'm glossing over a lot of details. If you want a much better researched (and presented) depiction of the Mongol's descent into decadence, I'd recommend: Dan Carlin's Hardcore History - Wrath of the Khans. It is an extensive and terrifying description of a specific example where a super hard-core civilization gets introduced to the niceties of agricultural society.

Answer 2

In fact, I think the most realistic outcome is that the warring civ would become the ruling society in the peaceful society and use the conquered citizens as workers. For example, it happened with the Spartans/helots, the Germanic tribes after the fall of the Western Roman Empire or the Mongols conquering... well, everything in their path.

But if you need the peaceful civ to be expelled, there is one thing: even if they are in the wasteland, they have more advanced technology. Perhaps they can develop irrigation or artesian aquifers that make barren land fertile again. Perhaps they know how to dessecate swamps or have plants that grow in different terrains (like rice or algae that live in brackish waters next to the sea).

Or they could became masters of trade, for example building very good ships and techonological advancements like different sails that allow them to sail where others can't. When the Huns destroyed their city, the future Venetians moved to a very bad location, but they became a naval power in the Middle Ages.

Also sedentary societies develop complex religions and it could be a decisive factor for people to be united through harsh times.

Your warring civ can keep on being nomadic even in fertile lands if they keep the amount of cattle as the value of the society (as it happened initially with the Mongols) or if they make slaves/women/old people work the fields while they devote themselves to physical prowess (like the Germanic tribes described by Tacitus). The military tradition could stay honed by periodic raidings on other lands or prestigious competitions.

Answer 3

The most probable set of circumstances where this could be the situation is where the arid lands can only support a small, resource impoverished population. While the fertile lands support a well-equipped, well-resourced, well-organized military society.

Let's call the rich military land A and its poor arid neighbour B. Simply so we can identify them. Instead of a China with its abundant resources and few military competitors, let's model its society on a highly organized, highly militarized culture like that of the Zulus. This will ensure instead the arid dwellers in B become raiders and plunderers like the Huns and Mongols on a big rich sitting target that was China. Now the raiders will come from A to raid and plunder whatever little in goods, chattels, and resources that were held by the folk in B.

To survive A will need to have strong, well-resource neighbours who in tern live on fertile territory. The attacks and raids on B will only occur when there are resources the empire of A needs. Conscript soldiers to fight in their wars or resources like horses (the Mongols had magnificent horses to their advantage).

Essentially an aggressive rich military nation can force compliance and a peaceful way of life on their poor, resource-impoverished neighbours who are then have no alternative but to submit. Especially if the poor neighbours B do not have the capacity to mount and maintain a sufficiently strong army to defend themselves against the depredations of their powerful neighbours A.

Answer 4

I don't know how much the land will be needed to make the peaceful civ become harsh - after all, they've lost their homes, the tools and safeguards they would have had for surviving, and almost certainly many of their people were killed in this "dispossession".

Peacefulness very, very rarely overcomes the desire for revenge (even if acting on it isn't practical), and even more rarely will it overcome self defense or survival. I'm not sure you can separate the influence of the land swap from the circumstances that caused it.

I would expect the peaceful civ to very quicky become the formerly-peaceful civ in simple self defense, and I think it would happen even if the land they were pushed out into had been fertile with plentiful resources (well, if the invaders had come from a different direction than the peacefuls got pushed). After all, the formerly-peaceful people have just had a very bloody lesson on what being peaceful would cost if one's neighbors decided not to be.

It would, really, take extreme fanaticism to maintain a pacifist culture in the light of such consequences, and again extreme measures to not have individuals, or subsequent generations, decide for a more survivable ideal. Enough that I wouldn't call them peaceful, just with aggression turned inwards instead of outwards.

On the other side, I do agree with Green that warriors will soften as long as their skills weren't needed (and if, if your peacefuls remained so, they wouldn't have a real reason). They have what they need, so effort to stay in fighting condition, or remain nomadic, becomes extra and then optional as those who prepared for war less and for living more prospered over those who sunk resources into being battle-ready without a battle.

But, if your peacefuls do become formerly-peaceful, the warring civ may very well stay warlike, since they would have to deal with raids, sabotage, revenge attempts and so on from their dispossessed neighbors. It may make sense, over time, for the nation of warriors to become a nation of soldiers (that is, less about individual ferocity and more about organization and planning).