As you can see from the attached photograph, the bad guy was in fact to Jens Stoltenberg what the Tibetan fox is to the red fox. The character's name is Johanes "Jannik" Jansen, he's apparently some sort of bigshot in the politics of his local area (but certainly not of the country as a whole), and he is played by Gard B. Eidsvold.

So there's a few possibilities here to explain my incorrect memory:

  1. Being a small autistic child constantly overwhelmed and overstimulated by all the new information I was exposed to on a day to day basis in two languages, I somehow missed or didn't understand the character's actual role in the story, and concluded that him being a political bigshot of any capacity meant that he was the prime minister, and because I knew Jens Stoltenberg by name more than by face, I just assumed that he was the guy in the movie.
  2. While watching the movie, I only believed that the character looked kind of like Jens Stoltenberg, or that the character was based on him; or someone else remarked something to that effect, and then after several years, this memory was corrupted into me actually believing that the character was supposed to be Jens Stoltenberg; then to me believing that the character was Jens Stoltenberg played by himself; then to the character actually being Jens Stoltenberg played by himself — leading to me only finding out through a lot of painstaking googling earlier today that this wasn't the case.
  3. Some combination of the above, e.g. that the person sitting next to me remarked "he looks like Jens Stoltenberg", and I misinterpreted this as that person saying it actually was Jens Stoltenberg, and I believed this without question.
  4. Jens Stoltenberg actually is in the movie exactly as I remembered it, but is a distinct character from Jannik Jansen. There's no way of knowing for sure unless I rewatch the movie, right!
  5. I originally came from a timeline where the movie Radiopiratene featured 34th Prime Minister of Norway Jens Stoltenberg as himself and characterized as a tyrannical, stuck-up, cartoonishly evil, heartless bastard dead-set on ruining the fun of children; but I was shifted at some point into this timeline in which I now reside, where this movie from my childhood was in fact considerably less interesting... In which case I wanna go back.