Who Are We?

In what sort of situation might someone ask the question “who are we?” It seems most appropriate in the mouth of someone trying to shape her audience into a more coherent community. It is the sort of rhetorical question a party leader might ask at a party rally. In such situations, it means something like “what unifying ideal can we find to make us less like a mob and more like an army, less like people thrown together by accident and more like people who have united to accomplish a task?”