I would just add two things very briefly. First, three years ago we saw Estonia attacked by the Russians in the largest cyber-attack we've ever seen. This led NATO to establish a cyber-defence centre in Estonia. So we may not see a military attack. We may see a cyber-attack. The Russians will be creative, and we have to be prepared for that.
Second, since Ukraine we've seen the Government of Finland as well as the Government of Sweden reach out to NATO and talk about whether it would be possible for them to join an accession track. I think showing an interest in their interest, as Professor Doran says, should send a signal to Moscow that would be very useful. They are good allies potentially, good NATO members, and having them positioned right near the Baltics would be very helpful in the event that it came to blows.