Look into the back pages of any recent United States Passport and you will find the following notation:
“A person is considered a dual national when he owes allegiance to more than one country at the same time. A claim to allegiance may be based on facts of birth, marriage, parentage, or naturalization. A dual national may, while in the jurisdiction of the other country which considers that person its national, be subject to all of its laws, including being conscripted for military service. Dual nationals who encounter problems should contact the nearest American embassy or consulate."
Although the U.S. government has discouraged dual nationality in the past, it would be fair to say that the current position is one of toleration, although not to the point of endorsement. From the U.S. government’s view, dual citizenship is permitted as a fact of modern international relations, but not encouraged because of the still existing complications that may arise. This shift from active disapproval to increasing acceptance appears to reflect the long recognized status dual citizenship has had in international law, along with the rapid expansion of international trade, travel and communication in our globalizing world.
You may be a dual national if you possess passports from two nations, both of which are valid according to the laws of each of the two nations. Note that the operative idea here is that each country has the right and privilege to define the scope its own citizenship and nationality laws, and no other nation may prescribe the effect of these. It is for this reason that there is no separate document that identifies anyone as a dual national, no “dual citizenship card" or dual passport.
Some nations continue to have prohibitions on dual nationality on their books, and there continue to be restrictions of property ownership and tax implications for some foreign nationals who take on an additional nationality. When you are considering naturalization in the United States, you should be sure you understand the implications this will have if and when you return to your home country, whether as a returning resident or as a temporary visitor.
Someone considering a change of nationality would also do well to consider the effect of their decision on their children, either existing or yet-to-be-born. The United States recognizes everyone physically born within our national boundaries to be U.S. citizens at birth. Also, a child under the age of 18, who is a permanent resident, residing in the physical and legal custody of a parent who naturalizes, is considered a U.S. citizen by operation of law. If there is a desire to retain a child’s original nationality in addition to the new U.S. citizenship, there may need to document the birth with the original nation’s overseas representative through the embassy or consulate.
Remember that it is the right and prerogative of each nation to determine who is, and who is not, qualified to be its citizen, and to describe the documentary requirements needed to establish this. Many, but not all, nations allow children born into dual nationality situations to defer making a permanent decision on their nationality status until they reach the age of majority. If this applies to your family, you should be careful to be informed about the possible options.
Overall, dual nationality is becoming more and more common in the modern world, but complications as well as advantages are involved. Be sure you know the specific application of the rules to your situation as you navigate the ever-evolving world of international migration.