The Trojan War was won by the Greeks after a 10-year long battle. The decisive turn in the war was the charge led by Odysseus from the Trojan Horse.
"Grass" is actually a poem that was written by Carl Sandburg. This is a poem in which he has published right after the World War I which is in the year 1918. Based on this poem, you can sense an unforgiving tone in it. Therefore, I can say that the attitude that the author expresses is "anger". Hope this answer helps.
