I guess this is one of those Libertarian leanings I have as a Conservative – if a territory such as Puerto Rico wants to leave, well, have a nice forever (emphasis mine, reformatted):
Puerto Rican Activists Seek Help from The Hague for Reunification with Spain
A group of activists in Puerto Rico unhappy with the current status of the island as a United States commonwealth is demanding a separation from America and reunification with Spain. The group plans to contest the 1898 Treaty of Paris, which handed Puerto Rico to the United States, at the International Court of Justice. According to Fox News Latino, the group, the Puerto Rico Reunification With Spain organization, is seeking to be annexed into Spain given the ethnic history of the island and its separation from Spain through war. Unlike its neighbors Cuba and the Dominican Republic, which fought wars of independence to assert their sovereignty from Spain and Haiti respectively, Spain lost Puerto Rico in 1898 as part of its loss in the Spanish-American War as declared in the Treaty of Paris. Puerto Rico became an American territory and its residents United States citizens, but the territory never became a state.
The US does not formally recognize the ICJ so I’m not sure that would be all that persuasive (although, given the transnational / post-Constitutional elites in DC, anything is possible with this Administration). Yes, I know that our Civil War was formally fought over, not slavery, but





