I am fairly new to Axis and Allies, but in most of my experience thus far, Finland/Norway seems to matter little to any country. It’s a nice little 2 IPC’s for whoever controls it, but it doesn’t seem to factor into the big picture in many of the games I’ve played. Generally, if Russia is defending Karelia well, Germany really can’t really use the land units there offensively, especially if they have no transport in the area (which they shouldn’t unless the Allies have really goofed or have the worst dice rolling luck ever). However, unless Russia is having a really good day, they probably can’t spare the infantry to take over Finland/Norway until Germany’s goose is so cooked it doesn’t matter who takes Finland/Norway. Unless Germany is kind enough to allow the UK to have a navy, the UK can’t land any troops there, and any air units they would use to soften it up for an assault by the US or Russia could probably be better used elsewhere. Finally, the US has the troops to spare and the ability to get them to Finland/Norway, but why land troops there instead of somewhere in Africa, Western Europe, or even Spain if you have 3 IPC’s to spare. There are more IPC’s to gain elsewhere that are also more strategic.