BRUSSELS (AP) — If Scottish voters this week say Yes to independence, not only will they tear up the map of Great Britain, they’ll shake the twin pillars of Western Europe’s postwar prosperity and security — the European Union and the U.S.-led NATO defense alliance.

In breaking away from the rest of the United Kingdom, Scotland would automatically find itself outside both the EU and NATO, and have to reapply to join both, officials from those Brussels-based organizations have stressed.