Originally Posted by
hfly
2) I say this everytime this subject comes up. No country gives any real thought to what any other country does regarding its own citizenship laws/requirements. Germany has its laws, and many tens of thousands of Turks have "renounced" their Turkish citizenship in order to become German citizens. Guess what, they can get their Turkish passports back the next day as Turkey does not allow its citizens to permanently renounce citizenship (Once a Turk, always a Turk). Many countries (such as India) have similar provisions.
And thereby loose their German citizenship. German authorities are very strict if they find out that after you gave up your original citizenship to take the German actually reclaimed your original citizenship. This is illegal under German immigration law and will lead to loosing your German citizenship.
Originally Posted by
USAFAN
I have heard that Germans can now have dual citizenship. The source is generally well informed, however, I am not sure if it is true, but I believe it is!
You can have another EU citizenship without loosing your German citizenship. You can also apply for keeping your German citizenship if you for example taking the US citizenship. This has to be done in advanced before you take the second citizenship and is only available if you can prove that you have still close ties to Germany and giving up your German citizenship would cause problems while not having the second citizenship would also. For example you merry an US citizen and want to live in the US but your parents for example still live in Germany. In this case not being a US citizen can cause legal problems and not having a German passport could make visiting the parents problematic.
But back to the OP. When you are an US citizen you have to use your US citizenship/passport when entering the United States. To be honest being a US citizen and entering the US with a different foreign passport makes absolutely no sense in my opinion. In case of what the OP posted the airline just has to check if you have the proper documents to enter the US. For US citizens their passport, for foreign nationals in addition their visas and ESTA entries.