1.  In the first poem the soldier doesn't want to kill people anymore  and now he is aware of his actions. The second one, metaphorically speaking, describes the soldiers' pain. But it also  expresses  the nationalism.

2.  The first one is absolutely in a confessing tone, in comparison with the second one which erges the army to continue to be brave and not give up.

3.We choose the  13th  slide.