"Then again, it is often the attitudes of combatants, not civilians answering a poll, that may be most important--and those may be rather different"

Well, there is one aspect of wars that is often under estimated, it is the participation of civilians into it.
One of the aspect I have witness and experiment a lot is the useof farming as a civilian tool to conquier land and also urbanism.
This has been used by Kagame after the genocide to reorganise the population setlements in Rwanda. Instade of preserving the wide spread villages urbanism scheme that was the norm before with houses on the top of the ills and fields in the valley. He concentrated settlements into valleys and obliged people to rebuild villages in a "european style" where he could have more grip on them. Also, this allowed him to spoil land from the Hutu (not saying I like the interharmwe, far from it).
In DRC, the Nande reconquiered land in Ituri by being the very first one to come back,pushed by civilian authorities. This allowed them to occupy "legaly" villages left by the original populations that were too traumatised to come back. It also alowed them to occupy "free" land through agricultural relief programs by distributing farming land that they used to military loose but to which they had access as they were the political winners.
In South Somalia, it is not land access that has been instrumentalised but access to water. Kenyan somaly were denied development by their government as they voted to be Somaly in the 60. So they manage non maintenance of water points, increasing artificially drought. This results into increasing inter ethnic conflicts and "force" donors and humanitarian actors to come and implement every 4 years the same projects based on conflict mitigation, peace promotion and water access. They also manage to recover livestock. They either send on other part of the kenya/Ethiopia/Somalia triangle and keep somewick old cattles they let die to increase the symbols of drought.
Also, in an attempt to settle the conflict in Somalia, NGO and UN agencies tryed to talk to elders and traders. They found out that all those civilians were either fully supporting war or were basically trading with various groups to support their efforts of war or increase existing tensions that would serve their business.

So far, I do agree that military behaviour is one important aspect of war. But civilian behaviour is also influencing war and not always (far from that) unpurposely.
It is the same with the problematic of drug production. In somehow, drug production and insecurity resulting from it becomes a rational choice for poor farmers households. Soldiers protecting them are not always providing what is the most beneficial for them in an economic perspective.