"IMO if Turkey (a NATO member at present) blocked off the Bosporus to Russian Naval shipping, that Russia would invade Turkey even though Turkey is a member of NATO. That, more likely than not, would cause WW3."
I'm not an expert but I do know Turkiye has already refused entry ......correct me if I'm wrong but I don't believe any Russian naval ships have entered the Black Sea since the War began and I don't see World War 3 happening or any invasion of Turkiye as a result of that.
I do find it strange that you should want to support a country trying to take over another country. Do you have Russian ancestry , I'm trying to see why you should want to support this?