Considering the Black Sea isn't Russian waters, US warships have the right to navigate in these waters. As long as the US warships remain over 12 miles off any Russian Coastline they are well within the rights of of the Law of the Sea treaty to be in the Baltic Sea.
You have a right to poke an angry bear with a stick too. Doesn't make it a smart thing to do.
The main question is what's the bigger long term US foreign policy? Do we have one? Who is our geopolitical rival?
Is it really Russia? If so, then we should keep isolating it and re-fighting the Cold War. That's not a hard fight for the West to win. NATO will be in Ukraine soon, yippee! We are all so much safer now.
But if our geopolitical rival is China, then winning the fight to isolate Russia only pushes it into China's arms. Then China gets access to enormous natural resources on favorable terms, and Europe and the West get denied those resources. This is in our long term interest?
Is securing a transit country for Russian natural resources (Ukraine) worth losing access to those resources to your real geopolitical rival?
The biggest battle of 21st century geopolitics is going to be a fight FOR Russia, not a fight WITH Russia. Russia has more to fear from China than US, by far, and US has more to fear from China than Russia, by far. Russia and US are natural allies against China. But because both US and Russia haven't been able to end the Cold War and bury the hatchet, now Russia is going to end up in Chinese embrace, fueling it's economy and war machinery. To win the Cold War and have Russia eating from your hands in early 90s, and in the span of 20 years just hand it over to China, because it was oh so important to keep expanding NATO to Russia's doorstep, it's foreign policy malpractice.