I don't feel war is what we do to avoid suffering, because we all know it produces suffering. When has there been a war without suffering?
Seems then that we are willing to suffer to win a war. Could it be we believe we will have less suffering than if we lose?
If thats true then flipside is the losers are likely to suffer more than if they would win. So suffering is a net addition by the consequence of war, whomever wins or loses.
The problem is these beliefs we have about our future suffering are expectations that we never know will be real or not - even though we are convinced they are real at the time. Being so convinced makes them appear real.
Many of us wish we could accurately predict the future but it's very very rare anyone does. So these beliefs are more likely than not just false expectations appearing real, simply put - fear.
That means it's fear we are acting on to make war because we believe it will avoid suffering. But war always brings more suffering. So it's completely counterintuitive but that's the nature of fear - we act in fear to avoid an outcome that we inadvertently bring about by trying to avoid it.
So that's a good reason to never act in fear. By not acting in fear, we're more likely to get the outcome we really want, and not the one we reallt want to avoid.