And how many wars have been fought over that Isthmus?
Russia is fighting for it’s life much the same as we’re fighting for our lives except that we’re doing it through bullshit then ballot and they’re doing it with gunpowder and cartridge.
I’m not seeing the “Russians fighting for their lives” part, unless you mean after a hypothetical closure of the waterways. Currently, I see Russia as supporting old allies Syria and Iran, and maneuvering to gain a warmer water port.