deploying CVNs in the Baltic is not a good idea.
Or near it.
During WWII, the British had a carrier doing duty off of Norway. The fine folks at Bletchley Park decoded SigInt that indicated the KMS Scharnhorst et al were cruising down to engage the British ships, and promptly informed the Admiralty, which ignored the warning.
The British lost the carrier, and a handful of other ships.
Better late than never, the Admiralty started paying attention to Bletchley Park.