Fill in the blank. Applicants for naturalization allegiance to the foreign countries of which they were formerly citizens.

Citizenship usually means that an individual swears his or her allegiance to one country only. For people who want to be naturalized, they must renounce their allegiance to the country where they were originally citizens from, and pledge their allegiance to the foreign country where they will be naturalized citizens. If naturalized citizens want to re-acquire their citizenship, they have to renounce their oath of allegiance to the foreign country.