borderless country

A borderless country may be defined as an island nation, an insular territory over which a nation-state is sovereign under international law, that does not share the land territory of its island with other nation-states sovereign under international law. For example, the Republic of Ireland shares the island of Ireland with Northern Ireland and thus is not borderless. A borderless nation does not have to be located on single island, as countries such as the Federated States of Micronesia can consist of thousands of islands. Cuba is a disputed case of an island nation because the United States exercises effective sovereignty over part of Guantanamo Bay.

List of borderless countries

List of borderless dependent territories

Footnotes

Australia and New Zealand maintain claims to territory in Antarctica and as such can technically be regarded as having land borders there.
The Republic of China (Taiwan) has not formally renounced claim on areas currently under control of People's Republic of China, Mongolia, Tuva (a Russian republic), etc.
Guantanamo Bay in Cuba is a U.S. lease.
Aaland has some 10 meters border with Sweden on the Island of Mrket