This varies a lot based on the context, as you might expect. It is worth pointing out that a lot of the details which speak to your confusions are filtered out just because of the format in which you are consuming history; popular histories necessarily dispense with nuanced details behind popular opinion or decisions of rulers/governments/etc; they spare none at all for the individual soldiers. It is also worth pointing out that this is not even a little bit settled of a question; it doesn’t even have rigorous schools of thought—we (the civilizational we) are only in the process of clarifying this now.
That being said, I claim it is because of local incentives.
The simplest one is brutally straightforward: most of history’s soldiers were not volunteers but conscripts. In pre-modern times the bargain was this: come with the army or die immediately. Going to war, for the group of men who did, was mostly a matter of sparing their own lives and the lives of their village from their own army. In modern times we have refined this process considerably, but fundamentally it remains a matter of a highly probable harm up front versus a distant and uncertain harm in the future.
Volunteers are more nuanced, but they still act according to local incentives. Most of time it is because the army offers more reliable food, shelter, and payment than they would get by staying where they are; maybe dying of dysentery on the march isn’t as bad as definitely freezing or starving next winter. Since the development of the professional military the army is considered a career like any other, and gets put down next to doctor or engineer for officers, and welder or electrician for enlisted.
Volunteers who join for moral reasons (like me) can probably still mostly be chunked as responding to local incentives, where local incentives includes social incentives. A lot of people in this group do it because it is a family tradition, or because it is highly respected in the area where they are from. That being said, this is the group where the explanation is weakest, and I have to start wondering about larger social incentives, and all the sticky wickets that come with those.
I know this is kind of a fraught and ineffable subject, so I’ll say explicitly that questions are welcome even if they are about my personal experience. If there is discomfort with asking those questions in public, I can answer via PM.
most of history’s soldiers were not volunteers but conscripts. In pre-modern times the bargain was this: come with the army or die immediately.
There are many good answers in this thread, but this is the important part that was missing from most of them.
As I was reading about how we are optimized for war by evolution, how war is a way to get resources and signal bravery… I was wondering why do the governments even bother to convince their own population that they were attacked, instead of saying: “adventure and epic loot, join our attack on Victimistan!”
And although there are definitely people for whom “adventure and loot” is a sufficient motivation, they seem to be a minority in the population, so unless you are attacking a much weaker enemy, you need additional soldiers. Then your options are conscription, and increasing the social pressure by saying that the war is defensive. (Also, calling the war defensive makes the conscription politically more acceptable.)
Seems to me that the whole answer has three parts:
some people enjoy the war;
some people can profit from the war without participating in it directly;
and other people can be forced to fight, by a combination of threat and propaganda.
The first explains why the idea of war is not considered as repulsive as e.g. cannibalism. The second explains why the wars (against enemy too big to be defeated by the first group alone) actually happen; and the third explains how.
This varies a lot based on the context, as you might expect. It is worth pointing out that a lot of the details which speak to your confusions are filtered out just because of the format in which you are consuming history; popular histories necessarily dispense with nuanced details behind popular opinion or decisions of rulers/governments/etc; they spare none at all for the individual soldiers. It is also worth pointing out that this is not even a little bit settled of a question; it doesn’t even have rigorous schools of thought—we (the civilizational we) are only in the process of clarifying this now.
That being said, I claim it is because of local incentives.
The simplest one is brutally straightforward: most of history’s soldiers were not volunteers but conscripts. In pre-modern times the bargain was this: come with the army or die immediately. Going to war, for the group of men who did, was mostly a matter of sparing their own lives and the lives of their village from their own army. In modern times we have refined this process considerably, but fundamentally it remains a matter of a highly probable harm up front versus a distant and uncertain harm in the future.
Volunteers are more nuanced, but they still act according to local incentives. Most of time it is because the army offers more reliable food, shelter, and payment than they would get by staying where they are; maybe dying of dysentery on the march isn’t as bad as definitely freezing or starving next winter. Since the development of the professional military the army is considered a career like any other, and gets put down next to doctor or engineer for officers, and welder or electrician for enlisted.
Volunteers who join for moral reasons (like me) can probably still mostly be chunked as responding to local incentives, where local incentives includes social incentives. A lot of people in this group do it because it is a family tradition, or because it is highly respected in the area where they are from. That being said, this is the group where the explanation is weakest, and I have to start wondering about larger social incentives, and all the sticky wickets that come with those.
In terms of the decision-makers for whether there even is war, I like the post Power Buys You Distance From the Crime for modern, non-war corollaries.
In terms of what this feels like from the inside, I can offer a first-person perspective.
I know this is kind of a fraught and ineffable subject, so I’ll say explicitly that questions are welcome even if they are about my personal experience. If there is discomfort with asking those questions in public, I can answer via PM.
There are many good answers in this thread, but this is the important part that was missing from most of them.
As I was reading about how we are optimized for war by evolution, how war is a way to get resources and signal bravery… I was wondering why do the governments even bother to convince their own population that they were attacked, instead of saying: “adventure and epic loot, join our attack on Victimistan!”
And although there are definitely people for whom “adventure and loot” is a sufficient motivation, they seem to be a minority in the population, so unless you are attacking a much weaker enemy, you need additional soldiers. Then your options are conscription, and increasing the social pressure by saying that the war is defensive. (Also, calling the war defensive makes the conscription politically more acceptable.)
Seems to me that the whole answer has three parts:
some people enjoy the war;
some people can profit from the war without participating in it directly;
and other people can be forced to fight, by a combination of threat and propaganda.
The first explains why the idea of war is not considered as repulsive as e.g. cannibalism. The second explains why the wars (against enemy too big to be defeated by the first group alone) actually happen; and the third explains how.