Um...C? That's a weird question...
The figure of speech, if I am not mistaken is personification. JFK is stating that the country can do something(implying human characteristics), but the country CAN'T literally do something for you in the way that is implied.
To make the story intresting
There are two theme's to "The Gift of the Magi" one being Love and the other being Sacrifice. "The Gift of the Magi" gives it's lesson by showing that even in rough times there is still some "Love" in everyone's hearts.
By having the setting at Christmas time it shows the comparison to the men's gifts to Jesus.
Here is something to work off of because i am guessing you did not read it and are hoping for someone to do it for you.
Actually read it if you want a good grade.