Sorry - I got quite busy and forgot about this. I suppose that by now the game has continued to a point beyond the situation we were discussing. So what happened?
Can Russia build ships in sz 100 and then move through the straight?
Or do you have to own Turkey?
The Allies have to control Turkey at the beginning of the Russian turn for Russia to move ships through the Straits.
Also, according to the rule book: “If a canal or narrow strait is controlled by a power not on your side, but with which you are not yet at war, you must ask permission to use it, which may be denied.”
So in a very theoretical situation, Germany could capture Turkey before being at war with Russia, and allow Russian ships to pass through the Straights. But I don’t think that ever happens.