What does the American flag represent in the novel, Ducks, Newburyport?

The American flag symbolizes excessive nationalism in Ducks, Newburyport. The protagonist perceives the one or more flags that fly from each American home as emblems of conquest. She believes that these representations of her corrupt and troubled country are militaristic and thus inappropriate. Her lack of faith in American politics and culture leads her to question the loyalty other Americans maintain for their country, which they broadcast by prominently displaying American flags outside their homes.