Complex sentence: Humanity's "small talent" for war (crude weapons, petty bickering over borders) is not significant enough to be of any use to them, and he laughingly states that--worst of all--the people of Earth long for peace.
Split into simpler sentences: Humanity's "small talent" for war (crude weapons, petty bickering over borders) is not significant enough to be of any use to them. And he laughingly states that--worst of all--the people of Earth long for peace.