Garuda:
Now I'm kinda confused.
Hi, Garuda - yes, it
is confusing - but perhaps that was Hergé's point?
We've touched on this subject of Syldavian/ Bordurian politics, and the related politics of Alcazar and Tapioca, before, but as you put it in the context of WWII, your post has been moved to this thread, and you might find it interesting to read back.
Generally, I think it is taken that Hergé was adopting the position of an outside observer to suggest that the trappings of political ideologies - even those that we might see as opposed - often take the same form.
Were you to be an archeologist in the future, or an alien visiting from another planet, would it be possible to distinguish that the flags, uniforms, etc. of a Nuremberg rally, and a May Day parade through Red Square were not promoting the same thing? You could probably tell that a Red star, or hammer and sickle weren't the same as a swastika - but could you tell that they didn't promote the same ideals? I'm not sure that you could.
It's like the old joke: "It doesn't matter who you vote for - the government always gets in".
Hergé wants to say that the window-dressing may change, one party may get elected over another, one regime may overthrow another, but in the end it's the same - one group controlling another, one lot of politicians replacing another.
In the books it's probably best summed up in
Picaros, where he shows the same scene in the slums twice: the uniforms of the soldiers change, but are broadly similar, and yet the population continue to live in slums, whichever leader is in office...