In every country in the world, the nationality of the people born to that country is very clear. In China, the people are Chinese. In Korea, the people are Korean. In Mexico, the people are Mexican. In France, the people are French.
In the United States of America...the people are always something other than American and there is no way to self-identify as American.
I believe this has a more far reaching impact on the people of the United States of America. While the issues of race relations and tolerance are improving, the underlying problem still exists in that there is no national identity for Americans. It may be possible to correct this in part by allowing a national identity to exist whereby the people of the USA can self-identify as American as their nationality.