What makes the Caribbean a region

The two borders, and the water

The first runs down Hispaniola. Haiti and the Dominican Republic fixed it by a treaty of 21 January 1929, an agreement of 27 February 1935 and a protocol of 9 March 1936, and its published length depends on which map was measured: the boundary study issued by the Office of the Geographer at the State Department on 23 May 1961 gives 224 miles from a map at 1:100,000 and 171 miles from one at 1:820,000, and explains the gap as scale rather than movement, since the finer map picks up river bends the coarser one smooths away.

The second sits on Saint Martin, partitioned by the Treaty of Concordia of 23 March 1648. The northern part covers 53 square kilometres and the southern 34, and nothing on the road between them stops a car. Every other member reaches its neighbours across water, which is why the sea does the work a shared frontier does elsewhere.

Sovereign, and administered

Thirteen of the members are sovereign states. The rest are administered from four capitals: five from London, four from Paris, four from The Hague and two from Washington. What that administration amounts to differs inside each group. Guadeloupe, Martinique and Saint Martin are outermost regions of the European Union under Article 349 of the Treaty on the Functioning of the European Union. Saint Barthélemy was one until 1 January 2012, when a European Council decision taken on 29 October 2010 turned it into an overseas country and territory instead, with the euro kept by a separate monetary agreement. Aruba, Curaçao and Sint Maarten are countries within the Kingdom of the Netherlands, the latter two since the Netherlands Antilles was dissolved on 10 October 2010. Bonaire, Sint Eustatius and Saba became special municipalities of the Netherlands on that same day and share the ISO code BQ, so three islands arrive here inside one record.

Driving side follows the administering power rather than the map. Sixteen keep to the left and twelve to the right, and the United States Virgin Islands keep left while spending the United States dollar.

What is in the till

Eight of the members use the Eastern Caribbean dollar, issued from Basseterre by the Eastern Caribbean Central Bank and pegged at 2.70 to the United States dollar since 7 July 1976. Two of the eight, Anguilla and Montserrat, are British territories, so the currency union and the list of sovereign states cut across each other. The United States dollar itself is the money of five members, and the euro of four. Curaçao and Sint Maarten changed theirs on 31 March 2025, when the Caribbean guilder became legal tender in place of the Netherlands Antillean guilder at the same peg of 1.79 to the United States dollar. The remainder each issue their own.

Where the edges are argued

The M49 scheme published by the UN Statistics Division files the Bahamas and the Turks and Caicos Islands under the Caribbean although both lie in the Atlantic, north of the Caribbean Sea, and the catalogue follows M49. CARICOM draws a different shape from the same water: twelve of the members filed here are full members of it, and so are Belize, Guyana and Suriname, which sit on the mainland and are filed with Central and South America. Montserrat holds full membership while remaining a British territory. Anguilla, the British Virgin Islands, the Cayman Islands, Curaçao, Martinique and the Turks and Caicos Islands are associate members. Cuba, the Dominican Republic and Puerto Rico appear on neither roster. Both readings of the region are in print, and neither is settled here.