It's worth emphasizing this: without the US Navy, the remaining European powers don't have the naval force to stop Russia from blockading the Baltics. And without the ability to break such a blockade, there's little hope in aiding the Baltics against a land invasion from Russia and Belarus. Russia wants a land route to Kaliningrad, and they'll take it at this rate.
My understanding is that European Air and Ground forces have been able to deter or destroy Soviet/Russian Naval operations in the North and Baltic Seas since the start of the cold war. Land based anti-ship missiles have more than enough range to cover the entire water way on their own.
This was a major reason the Soviet Union and now Russia never invested in a large navy outside of Submarines.
Where would this blockade be? In the NATO sea (baltic sea)? Covered by European Nato countries at every direction, and then whole entry passes through Denmark.