This incident got a lot of media attention, but the explanations for what happened were mostly omitted by reporters. The Baltic Sea is completely carved up between littoral states into territorial waters and exclusive economic zones (EEZ), there are no international waters there, according to the Law of the Sea Convention to which almost all coastal states in the world are parties with the notable exception of the U.S.
Military exercises are not allowed in EEZs without the permission of the corresponding littoral state, which is precisely what USS Donald Cook has been doing there with a Polish naval helicopter. It is worth noting that the Polish helicopter vacated the area immediately upon sighting a Russian naval helicopter, long before the jets showed up. The Polish government voiced no complaints about the Russian conduct.
Now, the Baltic Sea is particularly suited for seasteading, because it is one of the calmest seas in the world and its littoral states have very different economic and legal systems, with plentyful opportunities for jurisdictional arbitrage and profitable trade. Being inside an EEZ of a state, while it does pose certain restrictions (e.g. no military operations without permission), is almost like international waters. If the state gets nasty, it is easy to move to another EEZ, putting the littoral states in a competition for seasteads. Currently, international waters are essentially under U. S. jurisdiction, with the U. S. Navy “maintaining freedom of the seas”, which may well (and sometimes does) entail interfering with certain types of trade, perfectly legal in other jurisdictions. For example, they very often enforce various embargoes in international waters. Actually, other navies sometimes do that, too.
I believe – though I readily admit that it is debatable – that a seastead in an area with many respected EEZs, free to move between them, is safer from government interference than one in international waters. What do you think?