In principle, US policy accepts that dual citizens may be legally compelled to perform military responsibilities abroad, and many can do so without compromising their US citizenship, but each circumstance must be thoroughly researched. The United States taxes its people on all money made anywhere in the world. This includes any income from stocks, bonds, or other investments; interest payments from debt securities; rent from real estate; royalty from patents or trademarks; and sales of products manufactured with foreign-owned factories.
The main disadvantage is that it's difficult to get out of it if you want to avoid serving in the armed forces. If you're called up under the US Uniform Code of Military Justice (UCMJ), or refuse to serve when asked, you could be declared inadmissible to the United States and deported. However, there are ways around this: for example, you could submit a DD-214 form (a document issued to military service members) stating that you were forced into service against your will. If you can prove this, an immigration judge may decide to grant you a discretionary waiver of inadmissibility.
Being a dual citizen means that you'll be obliged to obey the orders of the country where you hold your foreign passport, even if you disagree with those orders. If you openly oppose your government's policies, however, you might find yourself banned from entering your native country.
The United States government recognizes the existence of dual nationality but does not encourage it as a matter of policy due to the complications it may pose. Other nations' claims on dual national US individuals may clash with US law, and dual nationality may restrict the US government's ability to aid people overseas.
In addition, many countries require their citizens to give up their other nationalities by renouncing their passports. If these citizens enter or try to leave the country by air or sea, they will be denied entry or removed from the vessel at the border.
However, no such restriction applies to land borders. A person who holds multiple passports is called a "polyglot". Many polyglots live abroad because it is easier to travel using more than one passport. However, some countries will not allow their nationals to hold another country's passport, so these people are technically stateless.
Some states have laws that provide for the automatic loss of other states' passports if you apply for a new one. For example, if you move to Maryland, they will issue a new passport for you without asking about your other states' licenses. If Maryland loses track of you and cannot find any evidence that they should continue issuing new passports, then they can stop doing so and you will remain a citizen of those other states too.
It is important to keep in touch with your foreign embassies if you change your address or phone number.
A Quick Overview Although the United States accepts dual citizenship, not all nations do. 1st Dual citizenship occurs naturally in some circumstances, such as when a child is born in the United States to parents who are citizens of another country. 2nd Generally speaking, if you obtain other citizenship by naturalization (a process called "acquiring foreign citizenship"), then you lose your American citizenship. However, there are exceptions to this rule. For example, people who were born in America to at least one parent who was a citizen at birth can't be made citizens by default. They must take an action to apply for U.S. citizenship.
The process of losing American citizenship varies depending on which country's laws apply. But generally, you must fulfill some type of legal requirement to have your American citizenship revoked. This could include serving in the armed forces of a foreign country during a war or other act of violence where military service is required. It could also include committing a crime that renders you inadmissible to the United States. Finally, it could include voluntarily giving up your American citizenship if asked to by the United States government or if necessary to comply with some type of legal requirement.
People rarely lose their American citizenship, but it can happen if you move abroad and don't renounce your other citizenship(s).