The books of Ezra and Nehemiah are commonly noted for their negative view of foreigners. Attempts to explain this antagonism have pointed to the sociological dynamics of identity construction and preservation. Parallels are often drawn to reservations by ethnic minorities against intermarriage as a cultural survival mechanism. However, enforcing boundaries not only excludes, but also identifies outsiders. Thus, the exclusion of foreigners is not only a matter of maintaining ethnic boundaries, but also involves the ideological construction of identities, both of insiders and outsiders. The portrayal of foreigners in Ezra-Nehemiah is an integral part of the larger ideology of the book, that seeks to define the identity of the Persian province of Yehud within the larger context of Achaemenid imperial policy.