By your definition, we were all killers, even you, simply because we have to eat, don't you see?
How can we define "peace" without "martial"? How can we live in peace without those, providing us this luxury?
A tree lives in peace doesn't it? Many people live in peace. A zen master lives in and at peace. So there are many ways and many different examples.
The only people I know of being experts of the matter throughout history were ones who attained attained it as a real state of being. They are the experts and so I say not only is it possible but also obvious for those willing to look.
Peace is not a result of war. It's natural, it's a realm and thus is potentially there for all. War destroys peace, simple.
The answer to your question as with all truth is spiritual for that is the perception needed to see it.
Once looking at truth a person can then recognize the true meaning of something but until then can only intellectualize.
If you take my explanation from the last post then you will see that I said madness is war and thus definitions of martial to do with such take on a new meaning. Martial would be the discipline of not allowing any such mad views or acting from any such mad thoughts. So it becomes the the way of pure thought and harmony.
It becomes the way of 'despite my firmly held beliefs and conclusions and ways of thinking, despite what is widely held as true or normal, despite my not being able to see it, there is a way. Thus a path towards learning it. No excuses, no justifying yeah but what if, no but sometimes you have to blah blah blah. Basically....no madness. The discipline of masakatsu and agatsu.
Peace connects heaven and earth.
Those who can't see this are not at peace yet strive for it.
Peace has no violence or fight in it.
Yet those who crave it through their own internal lack of it think they can gain it through violence and fight.
No, you gain it by the discipline of living it and the facing up to your own thoughts and actions and those of others which tempt you to leave the path.
Peace is positive cause and thus actually all powerful.
The spirit of joy comes from it and love is it's heart. Aikido can be thus an expression of such.
There, I've said my peace