With all due respect to those who have answered the OP's question, I think you are missing his point. I am in a similar situation, booked on a 14 day Baltic cruise in June. The issue is not whether there is danger in visiting. The issue is that if the situation escalates further, as it looks like it may, there is a good chance that the ships may not be allowed to port in St. Petersburg as scheduled. While there are many other great ports on the itinerary for these cruises, most have a 2 day stopover in St. Petersburg, and the cruiselines charge alot of money for the Baltic cruises because of the stop in Russia. Yes, they "MAY" give another port in its place but they may not, instead opting to give sea days which earn the cruiselines more money since they don't have to pay berthing fees and we are stuck on the ship buying drinks all day. We just don't know what they will do if the situation arises, and they will not provide any answers as to what they will do if they can't stop in St. Petersburg. The problem is that final payments for the cruises must be made in the next week - month for most of the summer cruises
So maybe he is asking for your opinions on how you think the situation is going to play out to help him decide whether he should take a chance on not cancelling his cruise? I haven't decided yet - I still have 2 weeks before I have make the payment!