Putin, Psychology and European war

In a world where there are constant wars, why is it so hard to accept the possibility of war?
The idea, originally set out in China's Weaponized Economy of a failure of intelligence in groups is the likely culprit.
To understand this failing in human intelligence, it is a good idea to look at the probable causes.
There is the idea that we hide from what scares us.  That's a good place to start but it cannot be the entire answer.  Those who make guns must revel at the thought of war, at least the ones who are short sighted and miserly.
Another point is our reliance on one another.  We huddle in groups around campfires and in military formations of actual combat soldiers have to learn not to clump together.  We draw a perverse sense of safety from being together, depending on one another.
Then there are statistical concepts.  Those who would be willing to face their fears and stand apart from the crowd are few.  Those who will wake up at 5 o'clock in the morning to try to save those who sleep soundly (you know who you are) are marginalized and exist as outliers.  And they get tired of screaming "the end is near" with their real or apocryphal sign boards worn front to back.  I'm a little tired of it.
Those in power fear losing their power if they don't maintain a confident, positive message.  The last thing we want are politicians who say its hopeless.  The problem is that none of them wants to be the apocalyptic outlier and so they form a humming machine, incapable of addressing or even recognizing problems except as an averaged out group, the Naderian or Ralphian congressman screaming, "if we don't control pollution we're all going to die" ends up marginalized, sitting in his metaphorical bathtub watching the water rise, the bees die and, let's face, the end of the world coming from so many directions.  When the world ends, one imagines all of these friendless outcasts telling each other, "I told you so."  That's my plan.
In our brief existence between all the inevitable apocalypses perhaps it is better to forget everything, move to Amsterdam or Colorado, get a job as a postman, and just wait to be snuffed out.  But there is a little part of some of us, maybe even all of us, that is a part of that patriotic fever that herds us like cattle into war, but also makes us rail against the inevitable demise of our species.  That is the part that imagines us leaving this doomed world and even controlling this doomed world so it isn't doomed, at least not as quickly.
But I digress.
There are, then, only a couple of reasons that appear obvious for a lack of group intelligence and for our blindness.  There has to be something more.  Something must exist in our minds that shuts out things which are too terrible to imagine at some point in practical thinking.  Our brains must say "war is inevitable in Europe, we must plan for it or be constantly vigilant against it" and then they must say, "forget that or you'll get an ulcer.  Let's go down to the Patisserie and buy a croissant and a cafe' au lait, the Germans (or Russians) won't invade."  One has to imagine filters built in to allow us to function without paranoia, to assure ourselves that someone better informed is going to handle things, to be comfortable in the arms of someone else and the group around them, and lets face it, this time of the morning, going to the cafe for a doughnut doesn't sound like such a bad idea.