It is not uncommon for parents to be citizens of different countries. It is also too common for one parent to take a child back to their country of origin or to another country against the wishes or without the knowledge of the other parent. If this happens, you need a lawyer to go to court for you right away.
Gerald Nissenbaum, the founding lawyer for the firm, took a special interest in situations of parental child abduction both within the US and internationally. He was instrumental driving the Hague Convention on the Civil Aspects of International Child Abduction which is a multilateral treaty developed by the Hague Conference on Private International Law (HCCH) that provides an expeditious method to return a child internationally abducted by a parent from one member country to ther proper legal parent and country.
He also helped write its 1993 Hague Convention on Inter-country Adoptions.