It is a rare event in modern European history: a national border has just been legally created on French soil. A law published in the Journal officiel on July 22 finally establishes a formal frontier on the Caribbean island of Saint-Martin, a territory shared for centuries between France and the Kingdom of the Netherlands.
The French National Assembly voted last week to ratify the boundary demarcation, giving legal force to a 16-kilometer dividing line that had existed in theory but never in precise legal fact. While the island has been split since the Treaty of Concordia in 1648, the two colonial powers originally agreed to postpone the exact delimitation of their territories. That postponement has now lasted nearly 380 years.
A 2023 Agreement Now Enshrined in Law
The legislative move, championed by Horizons deputy Bertrand Bouyx, formalizes a bilateral agreement signed on May 26, 2023. The deal does not redraw the entire map but clarifies several disputed sectors, primarily in lagoon areas, transforming a historically approximate border into a legally incontestable one, according to overseas media outlet La 1ère.
The most significant territorial flashpoint resolved is the Oyster Pond (étang aux Huîtres), a bay on the island’s eastern side contested by both the Dutch and the French since 1775. Tensions peaked in the 1980s over the construction of a marina and a hotel on stilts. The French administration ultimately backed down, allowing the Dutch to issue official permits, which left several marina buildings in a legal gray zone for decades. Under the new accord, the border follows the median line of the pond, granting each state clear sovereignty over its respective half.
No Change for Residents, a New Tool for Administrators
For the island’s 75,000 inhabitants, the officialization of the border will change nothing in their daily lives. The free movement of people, without any border posts, remains a fundamental right across the entire island.
The primary objective of the demarcation is purely administrative. It aims to streamline the management of port infrastructure, clarify taxation rules, resolve building permit jurisdictions, and facilitate police interventions. To ensure the proper monitoring of the boundary, a joint commission will convene at least once a year.
