How different is the poetry of World War 1 from the poetry about war and battle written in other periods?

The poetry written in other periods prior to WWI was written to honor the soldiers and other who along with them fought and took part in the war. It didn't matter what capacity they served in; bravery was commended, pride was unquestionable, and honor accompanied duty to ones country.

With the advent of WWI, that type of poetry began to disappear. War was a 'new' kind of monster; it was cold and untamed, and it boasted numerous types of new technology. Killing was no longer personal because of the viciousness and complete destitution that followed the battles. Suddenly poetry took on a different, darker style, and the heroes of the past were loathe to find anyone joining their ranks of immortality in honor.