Denmark holds referendum on EU defense amid Ukraine war

COPENHAGEN, Denmark (AP) — Historically skeptical about European Union efforts to deepen cooperation, Danish voters on Wednesday will choose whether to abandon the country's decision three decades ago to opt out of the bloc's common defense policy.

The Danish referendum comes as the latest example of European countries seeking closer defense links with allies in response to Russia's invasion of Ukraine. It follows Sweden and Finland's historic bids to join NATO — something to be taken up at a summit next month.

Denmark joining the EU defense policy would have a relatively modest impact on Europe’s security architecture, particularly compared to Sweden and Finland joining NATO. But Christine Nissen, a researcher with the Danish Institute for International Studies, said both moves are “part of the same story,” and would strengthen military cooperation on a continent stunned by the war in Ukraine.

She said the main effect of abandoning the opt-out decision would be that Danish officials could stay in the room when EU colleagues discuss defense topics and Danish forces could take part in the bloc's military operations.

Denmark, a founding member of NATO, has stayed on the sidelines of EU efforts to build a common security and defense policy in parallel with the trans-Atlantic alliance. It was one of four opt-out moves that Danes insisted on before adopting the EU's Maastricht Treaty, which laid the foundation for political and economic union.

The 1992 waiver means Denmark hasn't participated in the EU's discussions on defense policy, its development and acquisition of military capabilities and its joint military operations, such as those in Africa and Bosnia and Herzegovina.

The Danes also opted out of EU cooperation on justice and home affairs, the common currency and...