Yes, indeed. And Russia violated the Treaty and now there's war in Ukraine. But it upheld the treaty regarding the Dardanelles strait, probably because Turkey i

Yes, indeed. And Russia violated the Treaty and now there's war in Ukraine. But it upheld the treaty regarding the Dardanelles strait, probably because Turkey is a NATO member and war with the NATO is really not something anyone wants, inlcuding Russia and the NATO. So in the Baltic sea, there's essentially two options: Either respect the treaties and keep the shipping lanes open or violate it and risk war with Russia. Until now, no critical infrastructure was attacked (the nord stream pipelines were out of use when they were blown up), so a less aggressive posturer seemed reasonable. Maybe that'll change now. Apart from that, the Dardanelles are 1.2km wide at the narrow point, the Gulf of Finland is 70km wide - blocking that is essentially impossible unless you go for a naval blockade and attack civilian ships.