US Citizens living abroad often choose to take the citizenship of their new homes to enable them to fully participate in the local society. However, immigration laws around the world are disparate, often illogical, and do not necessarily protect the rights of immigrants in accord with international law (i.e., the UN Declaration of Human Rights or the 1961 Convention on the Reduction of Statelessness).
For example, in countries that require proof of renunciation before naturalization, a rejected applicant will become a Stateless Person. Therefore, the US should protect former US Citizens by allowing them the right to return to citizenship, similar to the Right to Resume in the UK, or the Resident Return Visa in Australia (which is extended to former citizens, unlike in the US).