Like the tumultuous weather which rages through James Hurst's short story "The Scarlet Ibis," the mention of World War I by the boys' mother can be seen as a symbol for the war that is going on between the two brothers.
In the beginning of the story the narrator (or "brother") contemplates killing his younger brother because his mother says he might not "be all there." When "Doodle" turns out to be mentally normal but physically challenged he and the narrator develop a stormy relationship marked by periods of love and times of friction.
The mother mentions World War I at a time when the relationship between the two boys it at a crossroads (the "clove of seasons"). Hurst writes:
And during that summer, strange names were heard through the house: Chateau-Thierry, Amiens, Soissons, and in her blessing at the supper table, Mama once said, "And bless the Pearsons, whose boy Joe was lost at Belleau Wood."
The narrator has devised a rigorous training regime for Doodle but the boy is not up to it. Like the weather, which is sometimes blighted and sometimes turbulent, the reference to the war focuses the reader on the trouble between the two brothers, which ultimately ends in Doodle's death in a rainstorm after his brother pushes him too hard.