Motivations for interstellar war

Question

Let's imagine a future humanity that has just recently achieved FTL ability. They've recently begun expanding, and are ravenous for resources. They encounter an alien race, but they can't ascertain much about them. Any probes get destroyed, any long-range scans are blocked. Humanity can only deduce their presence by unusual radiation spectra and astronomical bodies cauterized by bombardment. What could motivate humans to attack these aliens? My current ideas are:

• The aliens' territory can be deduced by finding out where probes go dark. That territory contains something humans want very badly.
• The aliens attacked first.
• Humanity is gripped by very powerful xenophobia

Now let's imagine a stomatopod-like race that calls themselves the Zaux. Their world is one of such violent competition that it is like a perpetual warzone. Due to a biological peculiarity unique to this world, evolution happens thousands of times faster there than on Earth. Almost every species is in an arms race with almost every other species. The Zaux have achieved a relatively stable position in this environment, even if they are constantly at war. They rely on biological machinery for technology, and are capable of interstellar travel. Several other species from their world have naturally evolved such capabilities, and several more have developed non-natural means of doing so. The Zaux are expanding to acquire more resources, but must fight with their enemies every step of the way. Suddenly, a new, nosy, expansive race comes up out of nowhere (humans). The Zaux have limited resources they can divert to deal with them. What could motivate them to attack these newcomers? My current ideas are:

• Zaux could take resources from humans more easily than they could extract them on their own
• Humans are in area that Zaux can expand in without threat of their other enemies fighting them for territory
• Zaux do not realize that humans are an extraterrestrial race, and assume that they are hostile
• Humans attacked Zaux first

Finally, let's imagine that humans have details on the Zaux. They're a bit younger than humans, but they don't waste resources and allocate them with an efficiency humans have never been willing to force each other to do. They have also had the benefit of the faster rate of technological advances that come during wartime for the entirety of their existence. Consequently, they are thousands of years ahead of humans technologically. The only advantages we could possibly hope for are numbers, or that the Zaux are too engaged with more advanced enemies to pay us much attention. Given such knowledge, how would any human motivations for aggression against the Zaux change? Is there anything that could make them risk war? Or would they stoop to the lowest levels to avoid it?

Answer 1

The simplest way would be to take a page - or an entire chapter - from Orson Scott Card's Ender universe. Search for "Demosthenes' hierarchy of foreignness" for more details; below is a rough overview.

Basically, there are degrees of strangeness when it comes to other life. Aliens could fall into any category.

• There is the sort that we recognise as being just like us, but with a different culture. They might have a different language, but we can translate; they might have odd customs, but their basic morals and instincts are like ours. We can live with these creatures; it's no different from human foreigners.
• There is the sort we recognise as being like we would be, if we were from the same place. For example, perhaps their planet has very different conditions, so they have different base instincts - but ones that we can understand; ones that we'd have if we lived on their planet. We can live with these, once we adjust and find common ground.
• There is the sort that we recognise as being intelligent life, with whom we share some basic or important ideals. They may have a radically different worldview, or a totally different concept of what is moral. We can coexist with them as a species, but it may be difficult to live together. It will be hard to form a system of common ideas and concepts so that we can communicate, and it's unlikely that we'll be able to intuitively understand how they think, but it's possible.
• There is the sort that we recognise as being intelligent, but is too strange for us to comprehend. No matter how hard we try, we can't find enough common ground to form a basis of communication, and therefore we can't work out what they want. We can't coexist with them, because they could do anything - including kill us - and we can't tell them that we don't like it. Likewise, we could do things that they will not tolerate, and we have no way of knowing. We can avoid them, perhaps, but not live with them.

The general idea is that if your aliens are of the last sort, war may be unavoidable. If you can't find common ground with an alien race - if you can't communicate with them, even at the level of simply expressing ideas or emotions - then there is no way to negotiate. If they are sufficiently strange by human standards, then there can be no empathy or shared instinct between us, which means neither of us can predict how the other will act or react in a given scenario. They might not even realise that killing us is something we don't like, and without communication, we can't tell them. This makes them a threat, constantly, regardless of the situtation. If we can't live apart from them, and we can't keep them out, then our only remaining option is to destroy them.

Of course, once you resort to violence, you have to be sure that it'll work, particularly with an enemy that's unknowable, and doubly so if they have better technology or military power than you do. You need to remove their ability to respond as quickly as possible, or you're toast. Their motives may be strange to humans, but in general you can assume that any intelligent creature that hasn't been killed off yet must have some sort of survival instinct which includes the neutralising of threats, and you're about to make yourself a threat to them. If violence wasn't your last resort, you failed to resort to enough of it. In human conflicts, there's often a back-and-forth exchange, a slow escalation, with neither side wanting to overdo it for fear of doing too much damage to the land they'll have to live in afterward - or being seen as a dangerous aggressor by the international community. With an unknowable alien, you can't be sure that the rules of this game will be followed. They may meet your first strike with a retaliation by the full force of everything they have. Even if they don't, the longer the fight goes on, the more they wear you down, and the more chance they have to do something you weren't expecting. Therefore, you have to hit them as hard as you can in your first strike, to maximise your chance of success and minimise the uncertainties.

Answer 2

Because the very existence of alien intelligence is heretical and must be destroyed.

Answer 3

From your description the Zaux and the other species they evolved with are hypercompetitive to a degree unknown to humans. As such from a human viewpoint they would seem insanely aggressive and exploitative. A perfectly reasonable interpretation of this given the probable cultural and language barriers on initial contact would be to assume that the Zaux are preparing for imminent war.

And a perfectly reasonable response to that is a pre-emptive attack. This is because if you do not attack pre-emptively the opponent preparing aggressively will have decisive advantage and you will lose. When the enemy is largely unknown alien race, extinction of the human race would be highly possible result of that.

Basically, you simply need some reason why the Zaux and Humans do not start off being all friendly and trusting with each other. This results in humans distrusting the Zaux and their motives, which combined with the hypercompetitive nature of the Zaux results in fear and paranoia, which given any domestic political issues will easily result in a pre-emptive war.

Since the Zaux are only used to interacting with other hypercompetitive species, the above is pretty much assured. The Zaux will have no experience in peaceful and cooperative coexistence with humans. And humans will have no understanding of the Zaux and their behauviour. Just make sure that human politics are open to war and it will happen.

Incidentally, this supposedly almost happened to Soviet Union in response to Ronald Reagan suddenly for reasons incomprehensible to the Soviets adopting a highly aggressive stance and the decision to start a pre-emptive all-out nuclear attack to knock-out the US before the expected imminent US offensive was already made. Then the only person authorized to actually start the war fell too ill to do so, and we accidentally avoided the nuclear winter. And it is likely the communications gap between the Soviets and the Americans is smaller than between the humans and the Zaux.

So if you play up Zaux being aggressively hyper-competitive and humans having no idea why they are doing whatever they are doing and jumping to conclusions, you can easily have your war without any particular war-mongering.

And war-mongering is a thing, of course. If there hasn't been a major interstellar war within a generation or so, many influential people will grossly underestimate the cost of starting a war in relation to their short term political benefits. Lot's of examples of that in the history. For example if there has been a tendency to value strong military, but no real need for one recently, the military will be a solution in search of a problem, and a problem to justify using the military will be created given any significant excuse.

Answer 4

I dislike the idea of hate as a reason. Zaux is probably a lot like an ant population that attacks everything or evolves a symbiotic relation. They have a kind of Victorian mind set to the extreme. In that setting humans would probably be extremely unwilling to have anything to do with the Zaux.

Reasons for human to attack:

• Desperate to gain some essential resource like food or energy, space for living. Humans may not be unified, so if there is some population that is starvating, they could act without the approval of the humans in general.
• Anticipation that the Zaux will attack, humans have just revealed their existence for an aggressive alien race that will for certain attack, when it gets a change like the coordinates of earth or a moment where it can allocate resources for something else than the ongoing war

For the Zaux:

• Humans have already refined resources. The concentrations of minerals and metals in human artifacts are extremely high, compared to planets in general. Zaux can utilise this kind of resources fast for their war and get an advantage with rapid change as their enemies have no time to adapt.
• The habitat of humans are anyway a good place for expansion.
• Anticipation of the humans anticipation; the Zaux know that they cannot be trusted, so they want to get the first mover advantage

EDIT: The nuclear weapons that the humans possess are powerful enough to disrupt the Zaux significantly. The physics behind them is simple, so the Zaux probably has something similar, so it is unlikely that they would be motivated to get such. It could be though that they do not have uranium in their planet. As Zaux learn about the humans nuclear weapons, they have a motivation to push the war towards the earth; they do not want nukes to their world.

Answer 5

Star drives will be very expensive. Taking resources over interstellar distances is almost certainly not worth it unless you have some mighty cheap stardrive.

The only real reason for interstellar war is fear--either a xenophobic race who doesn't want anyone around, or a race that realizes that one of the others around is like that.

Answer 6

I think the chance of humans attacking the Zaux would be incredibly unlikely: for the simple reason that if humans attack first, some of the Zaux's neighbours will see the humans as an aggressive threat and possibly team up with the Zaux to defeat them ("if the humans are attacking the Zaux, what will stop them from coming after us next?"). The humans would have no chance of winning like this. The only reason I could see why humans would attack the Zaux would be if one of the Zaux's enemies offered the humans technology in exchange for military support- but this would require a high level of communication between the two species.

However, if the Zaux attack the humans first, the other races might not see humans as such a big threat. They'll probably keep to their own business. The Zaux, being so many years ahead of the humans, might be confident in their ability to wage a multi-front war. So the chance of Zaux attacking the humans is much greater than vice versa.

Now, for why the Zaux could attack the humans:

• Through piecing together and translating radio signals, the Zaux could learn something that disgusts them about human culture. Maybe they hate our inefficiency and wastefulness, or just have completely different morals to us. If they're zealous and offended enough, this could start conflict.

• The Zaux might want a way to test new military technology before actually using it on their enemies. They could see humans as a suitable candidate.

• If the humans manage to establish contact with any of the Zaux's enemies, even accidentally, the Zaux will see them as a threat.

Answer 7

Humanity can only deduce their presence by unusual radiation spectra and astronomical bodies cauterized by bombardment.

Avoid them by any cost.

Consequently, they are thousands of years ahead of humans technologically.

Avoid them by any cost.

In both cases best strategy is getting know both possible targets, avoid confrontation, buildup human capacities.

Very good if both of those situations take place simultaneously, so those for would like immediate war can test them self against Zaux in limited engagements, specially if for some reason Zaux do not consider that thread as some kind of part of external force. But it have be done very carefully in a way which prevents Zaux consolidation.

There is a problem with Zaux

As side note, description of Zaux I find it inconsistent

The Zaux have achieved a relatively stable position in this environment, even if they are constantly at war.

The Zaux have limited resources they can divert to deal with them.

Consequently, they are thousands of years ahead of humans technologically.

humanity that has just recently achieved FTL ability.

or that the Zaux are too engaged with more advanced enemies

But they certainly may be a problem in the future specially because of that

Zaux do not realize that humans are an extraterrestrial race

They rely on biological machinery for technology, and are capable of interstellar travel

So a space faring civilization, with blood lust and which is not capable to distinguish between different kinds of treats, with advanced technologies, which finds star system as limited resources, which can utilize war energy and matter waste more efficient then humans do - this may be a problem.

First anomaly

try different probes, which you may think of. Choose one type and send it once a year as example. After thousand years stop sending them, surprise them, let see are they smart and curious or not.

Answer 8

Well first of all you have the leaders who want any resources or new tech they can get. Even if they need to sacrifice some of their own people.

These Leaders would take the opportunity to create a propaganda war that plays on the fact that an alien race exists and is not willing to communicate. These aliens EVEN have the gall to destroy human probes. This shows not only do they have tech but that this tech is capable of destroying human tech. This would be used to create an up swell against the aliens which would lead to a state of war. This war can then also be used to solidify power within the human worlds.

As for the other races, they could contact the humans and offer support in defeating the Zaux.

Answer 9

In among the ever shifting alliances of the Zaux appeared an idealist with a dream. He dreamed of uniting their world under a single leader, himself. The Zaux were good at forming brief alliances, strong enough to overcome the immediate threat but they tended to collapse into infighting as soon as their task was complete, he needed an enemy, a strong external enemy that would allow him the time to secure his control.

The humans had come along, already started invading Zaux space (with probes), they'd already started attacking. Now to rally the Zaux to their greatest war ever fought, a war that required them to unite under a great leader (still himself).