What impact does undimmed have on the meaning of the poem

It illustrates how sudden the soldier's death was. It suggests the soldier is happy to leave the war. It shows that his death was peaceful.

the best description of postwar writers might be progressive.

following the war, writers showed a tendency to work on artistic or social matters rather than political themes. while postwar literature may not have been the greatest period of english literature, the themes provided excellent critics a high number of novels. such examples include anthony burgess, anthony powell and frank kermode, all of which can be placed under the progressive view.