The missing country is Belgium.
Benelux = Belgium + Netherlands + Luxembourg.
| Country | Capital | Population (2024 est.) | Area (km²) |
|---|---|---|---|
| Belgium | Brussels | 11.7M | 30,688 |
| Netherlands | Amsterdam (seat: The Hague) | 17.8M | 41,865 |
| Luxembourg | Luxembourg City | 0.66M | 2,586 |
All three are founding members of the EU, NATO, Eurozone, and the Benelux Union. Brussels (Belgium) hosts EU/NATO HQ; Luxembourg City hosts EU Court of Justice, EIB; The Hague (Netherlands) hosts ICJ, ICC.