The topic of war is something to look at from all sides.  These sides can include what we like to define as “right/wrong”, “defense/offense”, “freedom/dictatorship”, and so on.  The one thought that comes to my mind instead, is the existing absence for a fight in favor of humanity as a whole.  For now I only have time to introduce a quote that sparks further thought into the matter.

… Everybody is looking with a mixture of confidence and apprehension to the “statesmen” of the various peoples, ready to heap all praise on them if they “succeed in avoiding a war,” and ignoring the fact that it is only these very statesmen who ever cause a war, usually not even through bad intentions, but by their unreasonable mismanagement of the affairs entrusted to them. – Erich Fromm in The Sane Society