You wrote "Arts of war don't give birth, but quite the opposite: they kill people. " and quite so, but perhaps this is where the founder intended Aikido to be different from other martial arts?
Perhaps the true significance of Aikido lies in its constructive power - the fact that we day out and day in practise harmony - not only in words - but in physical movements with other people. As Nishio sensei have put it - "..in Aikido we posses the worst tool of all - the tool to kill people - but with this tool we instead create harmony, life and guide people to the see the beauty of humanity. Using the worst tool we create and shape the highest being - aikidokas are truely the greatest artists"