On Sunday, the Prime Minister of Denmark called on citizens to invalidate its opt-out from the EU defense policy in a referendum which will be held on June 1, which comes after Russia's military operation in Ukraine. 

"Historic times call for historic decisions," Mette Frederiksen told a news conference, where she said that the government clearly calls on Danes to "lift the opt-out on defense." 

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Copenhagen's opt-out, which is one of four special arrangements in the EU that has been negotiated by Denmark, has seen the country abstain from military operations, in addition to providing support and supplies to wars where the EU is concerned. 

"For me, as prime minister, this is a values-based decision," Frederiksen said.

The referendum comes as part of an agreement reached on Sunday, which is supported by the majority of the Danish parliamentary members. 

This referendum could potentially constitute a drastic turnaround in Denmark's defense policy which hasn't wavered for 30 years, coming at a time when other European nations, including Sweden, have also been switching up their policies to pitch into NATO's war against Russia in Ukraine.

Sweden and Finland, though not NATO members, have seen public support in joining the military alliance against Russia, seeing closer collaboration with NATO in military action. 

Olaf Scholz, German Chancellor, has also changed Germany's policy on defense, announcing a hefty brow-raising €100 billion defense while also sending weapons to Ukraine, recently sending over 2,700 anti-aircraft missiles.

This comes although Scholz stated that Germany would not be part of a military confrontation in Ukraine.

In addition, Frederiksen vowed to increase Denmark's defense spending by €941 million over the next 2 years, calling it the "largest investment" in Denmark's recent history. 

In line with NATO requirements, Copenhagen plans to increase spending to 2% of the Gross Domestic Product, by 2033, also stressing that Denmark needs to be independent of Russian gas ASAP.

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"We will also work towards this in the rest of Europe," Frederiksen said, referring to the gas dependency.

It is worth mentioning that in December 2015, the Danish population voted against strengthening their cooperation with the European Union on policy and security matters over fears of losing their sovereignty over immigration.