[jacknhoo]

“Not true as Russia can easily send subs from their ports.”

_______________________________________

You need to excerpt the whole paragraph, un-freakin’-believable:

“As for prospective “invisible” vessels, these could only loiter around with permission from Copenhagen – as the waters around Borholm are crammed with sensors, reflecting fear of incursion by Russian submarines.”

[tired&retired]

Duh... Russia is the most likely candidate. The water is at least 50 meters deep. There is a deep trench that runs toward Russia. It would be difficult for the US to get sub's past the shallow Denmark waters.

Does Denmark's sensors cover sub's in International waters?

You are an emotional decisionmaker and read what you want to read.