Germany has two infantry in Finland and marches them down to an empty Karelia and takes control. At the same time it transports two infantry from Berlin to Livonia. Does Russia get to roll for mines against the transport being that the minefield is adjacent to Karelia which just came under Axis control?
Yes, Russia rolls mines. The port is not neutralized until after the movement phase.
Question 2: The US, still neutral, moves into a sea zone with an Axis naval base. Are mines rolled while it’s still out of the war? My inclination is to think not, but my opponent said “well how do the mines know it’s not an enemy ship?” So here we are.
No, nobody rolls mines against America while they are not at war. Doesn’t really make sense that everybody would give maps of their minefields to the US, but that’s how the rules are.