Originally Posted by remyontheroad
Yes, it is an interesting subject.
If become a US citizen through naturalization, there is a stipulation that you renounce your allegience to any other country, but if you are born to citizenship in the US, then there is no way for them to force you to renounce any other allegiences.
I've always wondered whether anyone checks to see if you have actually renounced your original citizenship during the naturalization process.
I believe that it's a declaration that you sign as part of the process, but does anyone actually tell the other country?
It depends on the agreement. For example acquiring Spanish Citizenship (naturalisation) involves a formal Oath of Allegiance to His Majesty The King of Spain and thus renouncing any allegiance to a foreign state, etc; however while that voluntary oath, many would argue, signifies your renunciation of your current citizenship; the US does not particularly care. The US position is that if you acquire foreign citizenship AND do so with the intent to release your US, then you have lost it. Some countries do follow-up, Singapore is very diligent and requests proof of loss of citizenship, such as a "Certificate of Loss of Nationality" issued by many embassies. Singapore does not permit dual nationality beyond age 21 and you must choose.