a fine line

We've watched two film clips recently in my Mass Media class. One was about Hitler's propaganda films and the other was about Coca Cola's international marketing. It was unsettling to me how much these two have in common.

Now, before you start writing angry comments about how I shouldn't compare the horrors of Nazi Germany with something as trivial as soft drinks, let me say that I'm not putting the two on the same level.

But I need to ask why we view Hitler's propaganda war against the mentally and physically frail as a menacing evil, but sit passively as Coca Cola wages cultural warfare across the globe?

Why are persuasive tactics deemed sinister or saintly based on the motives of the speaker? What exactly is the difference between propaganda and public relations?

It keeps moving when I try to put my finger on it.