Citizenship of the United States
A person who is considered a citizen by more than one nation has "dual citizenship". It is possible for a United States citizen to have dual citizenship; this can be achieved in various ways, such as by birth in the United States to a parent who is a citizen of a foreign country (or in certain circumstances the foreign nationality may be transmitted even by a grandparent) by birth in another country to a parent(s) who is/are a United States citizen/s, or by having parents who are citizens of different countries. Anyone who becomes a naturalized U.S. citizen is required to renounce any prior "allegiance" to other countries during the naturalization ceremony; however, this renunciation of allegiance renunciation of citizenship to those countries.
Barack Obama citizenship conspiracy theories
It has been suggested that Obama obtained Indonesian citizenship (and thus may have lost U.S. citizenship) when he lived there as a child. As an attempt to prove that Obama was no longer a U.S. citizen (or held dual citizenship), some claim his 1981 trip to Pakistan took place at a time when there was supposedly a ban on United States passport holders entering that country, which would in turn have required him to use a non-U.S. passport. There was in fact no such ban. A "New York Times" article and U.S. State Department travel advisories from 1981 make it clear that travel to Pakistan by U.S. passport holders was legal at that time.