Looking at the map around Odessa and
Transnistria, there aren't many roads at all, to cross the rivers. (Hard to find a goog map showing the border of Tr'ia in detail, at the southern end.)
Transnistria is pro-Russian enough (about 40% in the south) that Putin could fly stuff in and occupy it, though technically it's part of Moldova.
It wouldn't take very much to isolate Odessa with the right equipment. Meanwhile they can lob missies at strategic targets from the Black sea, isolating and flattening parts of it as they go..
The land troops aren't there yet. Eyes on their progress at their western extremity, in Kherson, Mykolaev.(sp?)
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I don't see ajohn's comments as supporting Russia. We are seeing a lot of biased news.
We all know that more of Europe has westernized over the last 'n' years. We may see that as those countries determining their own future, but from Putin's side it the thoughts and rhetoric are that it's a Washington-driven pressure. His/their frustration, reaction and made-up stories aren't entirely rational, but maybe even he believes them now. many do. Someone interviewed in Donbas said that the US was about to base nuclear weapons near where she lives.