I have Canadian and American citizenships and plan on obtaining a third citizenship in a country that requires me to renounce my present two citizenships. I want to know about the process to get back my Canadian and American citizenships after obtaining the third. I plan on obtaining a Republic of China citizenship. I assume it is essentially a formality and I will only temporarily lose citizenship, fill out some forms and then immediately gain them back. Is this the case or what is it like? The reason I would renounce any citizenship is to get a third since the Republic of China requires it, I would gain Taiwanese citizenship via residency since I and both my parents are originally Canadian.
I assume it is essentially a formality and I will only temporarily lose citizenship
fill out some forms and then immediately gain them back.
Actively renouncing citizenship means you renounce any rights and entitlements that come with the citizenship. It's not a "mere formality". You become a non-citizen, just as any other non-citizen.
To get a US citizenship you'll need to go through the naturalization process, which, for most parts, requires 3-5 years (depending on the path) of permanent residency in the US as a prerequisite. To get a permanent residency in the US is not a very easy task.
Canadian naturalization process is similar, except that the time on permanent residency required before naturalization is shorter, and getting the permanent residency is somewhat easier (not by much, though).
Keep in mind that if Taiwan doesn't allow dual citizenship, you'll have to renounce your Taiwanese citizenship if you get any other.
To formalise the legal answer, here's the page on renunciation, and it's important to note this:
Finally, those contemplating a renunciation of U.S. citizenship should understand that *the act is irrevocable**, except as provided in section 351 of the INA (8 U.S.C. 1483), and cannot be canceled or set aside absent successful administrative or judicial appeal.
Long story short, you'd have to go through the process of getting citizenship - the long, arduous process - like any other non-US citizen.
Getting back formally renounced citizenships is difficult. However, claiming that you have renounced or will renounce other citizenships is easy, and in many countries this is all you need to do, since the new citizenship is typically granted before you renounce.
(Disclaimer: I'm not familiar with the process in Taiwan, so this may or may not apply to your specific situation.)