Finland Joins NATO

Brussels, Belgium – 4 April 2023

Finland deposited its instrument of accession and became NATO’s 31st Ally. Accession followed rapid ratification by Allies after Finland applied in May 2022 in response to Russia’s full‑scale invasion of Ukraine.

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Implications

• Strengthens defence of Northern Europe and Baltic Sea security.
• Expands Allied territory and border with Russia, affecting regional planning and posture.

Source

• NATO press release, “Finland joins NATO,” 4 April 2023.