The naturalization oath ceremony is one of the most significant and profound moments in one’s journey towards American citizenship. It is the end of the immigrant experience and the final threshold before citizenship. However, the oath also requires a serious commitment from the immigrant to forever renounce former allegiances, and also insists that the naturalization applicant take the oath without mental reservation or evasion.

The current format of the oath of allegiance is as follows:

“I hereby declare, on oath, that I absolutely and entirely renounce and abjure all allegiance and fidelity to any foreign prince, potentate, state, or sovereignty, of whom or which I have heretofore been a subject or citizen; that I will support and defend the Constitution and laws of the United States of America against all enemies, foreign and domestic; that I will bear true faith and allegiance to the same; that I will bear arms on behalf of the United States when required by the law; that I will perform noncombatant service in the Armed Forces of the United States when required by the law; that I will perform work of national importance under civilian direction when required by the law; and that I take this obligation freely, without any mental reservation or purpose of evasion; so help me God.”

For people who may wish to keep their former citizenship while becoming American citizens, whatever the reason may be, the question is what is the effect of the oath on their foreign citizenship as the oath requires the intending citizen to “absolutely and entirely renounce and abjure all allegiance” to any country that he or she has been a citizen. At the same time, there is nothing in the oath requiring a person seeking to naturalize to give up their foreign citizenship and having to cease being a citizen of that country.

The concept of dual citizenship or dual nationality has long been recognized, and the State Department in recognizing dual nationality acknowledges, “A U.S. citizen may acquire foreign citizenship by marriage, or a person naturalized as a U.S. citizen may not lose the citizenship of the country of birth. U.S. law does not mention dual nationality or require a person to choose one citizenship or another.”

Many European and other countries, in allowing dual citizenship also do not seem to mind when their citizens take up the citizenship of another country, including American citizenship, which requires the taking of the oath of allegiance. For example, German citizens may take up US citizenship while retaining their German citizenship, they just have to apply for a Beibehaltungsgenehmigung showing cause for the importance of retaining German citizenship and acquiring US (or any other foreign country for that matter) citizenship. In this application, personal information such as name, address, date of birth, the length of residence outside Germany, the applicant’s ties to Germany, and detailed reasons why the applicant has to become a citizen of US or another country are to be stated. However, no declaration of primary or exclusive allegiance to Germany is required nor does the procedure demand or expect any act in derogation of US citizenship.

Likewise, at no time is the newly naturalized American required to give up his or her foreign passport nor is the subsequent use of such passport a potentially expatriating act under INA 349.  INA section 349 specifies several conditions under which a US citizenship may be lost. These include:

• becoming a naturalized citizen of another country, or declaring allegiance to another country, after reaching age 18;
• serving as an officer in a foreign country’s military service, or serving in the armed forces of a country which is engaged in hostilities against the US;
• working for a foreign government (e.g., in political office or as a civil servant);
• formally renouncing one’s US citizenship before duly authorized US officials; or
• committing treason against, or attempting or conspiring to overthrow the government of the US.

If Congress had wanted to make post-naturalization travel on a foreign passport a potentially expatriating act, it knew full well how to do so. Under the doctrine of expressio unius est exclusio alterius (“the express mention of one thing is the exclusion of all others”), such a conspicuous omission is a clear indication that the naturalized citizen does not endanger his or her American citizenship by future travel on a foreign passport, so long as she leaves and enters the United States on an American passport as required by INA 215(b).

It is further confirmed by the Supreme Court that dual citizenship is “a status long recognized in the law…the concept of dual citizenship recognizes that a person may have and exercise rights of nationality in two countries and be subject to the responsibilities of both. The mere fact that he asserts the rights of one citizenship does not, without more, mean that he renounces the other… when one has a dual citizenship, it is not necessarily inconsistent with his citizenship in one nation to use a passport proclaiming his citizenship in the other…” (Kawasita v United States, 343 US 717, 753(1952) and even voting in foreign elections is no grounds for losing US citizenship,

(Afroyim v. Rusk, 377 US 163(1967) and the State Department has adopted an administrative premise that a “routine” oath of allegiance to a foreign country that does not explicitly require the renunciation of US citizenship will be presumed to have been performed with the intent to retain such citizenship (22 C.F.R 50.40(a) and 7 FAM 1222).

The final question is why do we even need citizenship as a basis for defining the people of a country?