Indeed, the missions are not completely random, they are assigned according to the current situation of the war.
As a bonus, you can see on the north sea map the progressive advance of the soviet troops when they conquer land or make a successfull sea invasion (meaning you failed to stop them), or the nato advancing when they manage to counter attack (thanks to your successse).
Daemon, just reading your description made me want to launch RSR again
This time i will take a better sub instead of the very old Permit class, and will see if i can survive a higher difficulty level with it.