Having dual citizenship gives people practical advantages such as more employment opportunities, easy travel and entitlement to the social programs of both countries. But possessing two nationalities has some disadvantages too. While the United States government recognizes dual citizenship, it does not encourage it because of the potential difficulties that it may bring. (Reference 1)
Limitations in Assistance Abroad
Each country has its own laws and rules involving crimes or misconduct. If a dual citizen commits a crime, it may be uncertain under which laws he should be prosecuted. Claims of the other country on a dual national may hinder U.S. government’s efforts to help its citizen abroad. While a dual national owes allegiance to both the United States and his other country of nationality, the country where he is located generally has a greater claim to his allegiance. The country where the dual national is located will consider you as its citizen, and thus, may not welcome outside interference. (Reference 1)
The U.S. government requires a dual national to report all worldwide income in her annual income tax return. Depending on the laws currently prevailing, the amount of income, and the source of income, a dual national may end up owing taxes to both countries. (Reference 2 under responsibilities)
Restrictions in Government Service Employment
Accepting employment with the government of his second country may result in the loss of a dual citizen’s U.S. citizenship. The United States Immigration and Nationality Act states that a U.S. national may lose his citizenship if he performs certain acts including accepting employment with a foreign government where he is a citizen of. (Reference 3)
Exposure to Political Upheavals
A dual national may be affected if the other country where she is a citizen of, is experiencing political upheavals or is suffering from military conflicts.