In the past, you were called a “citizen” of the USA if you were born in the USA. But that definition has been found to be seriously flawed by the invasion of illegal migrants seeking to gain citizenship via their anchor babies. Given that situation, the time has come to derive a better, more logical definition of what is required to be a citizen.
It only stands to reason that a new born’s citizenship should be the same as the parents, regardless of the country of birth. The problem is which parent in the case of a multi-national marriage. Certainly, dual citizenship is not smart. Here is an example. Able is a male citizen of Russia & married to Becky who is a female citizen of Mexico. While in the USA, they have a child called Sidney. So what citizenship should Sidney acquire. Many would say automatically Sidney should be of the same citizenship as the mother, in this case Mexico. But here is the problem. What if Sidney is born out of wedlock? Or what if Becky dies in giving birth? Even worse, what if both Becky and Able die as Sidney is being born? The correct answer appears to be, Sidney should acquire the citizenship of the parent in custody of and responsible for Sidney’s care. But this should only be allowed within the period of birth. Once it is set that is it unless Sidney as an adult chooses to become a naturalized citizen.