Those of you trying to throw out examples of situations with a russian actress or whatever, it's not going to work too well. Obviously, the North Vietnamese were thrilled to have an American helping their side.
It is a subjective opinion thing. Objectively, I can say there's something disgusting about someone who accuses people who go to war of being liars and hypocrites about what happened there, based on the word of the people they're fighting.
Those of you who are saying "There's nothing wrong with what she did, no one should be angry", please put yourself in the shoes of the average US conscript. Stuck in Vietnam, not because they want to, but because the alternative would be to go to jail. Everybody you knew is probably still back in the US, along with whatever romantic friend you have. All you really want to do is go back home.
So then Jane Fonda gets on the radio and starts talking about how the North Vietnamese really aren't that bad, and denouncing you and everybody else in the military. She's not even acknowledging the conditions you and the rest of your unit are fighting in; instead she's off posing in pictures, getting on the radio to tell people how bad you are, supporting the North Vietnamese.
I'm pretty sure I read something about her advocating people burning their draft cards and going to jail rather than serve. Which is great...except she ccouldn't be drafted. Very interesting.
If she had been protesting the US's involvement in the war, that would be one thing. But I've gotten the impression that she pretty heatedly castigated everyone who participated in the war in any way for any reason, and now that she's apologized expects to get off scot-free. Meanwhile, everyone who actually participated in the war had to deal with the prejudice that she helped stir up.
Here's a fun counter-example. For a school project, I interviewed a Vietnam veteran who also happened to be a draftee. He won a couple medals (Air medal and Bronze star medal), had the experience of being spat on as he arrived in the US, took him something like ten years to really recover from the shame of having participated in Vietnam, and is looking at an early death and degraded health because of the chemicals used at the time.
Had Jane Fonda served, I would suspect she would have experienced the same things - assuming that she came back. But she didn't. Instead she apparently called for people to hate veterans, and while that's not illegal, it seems to indicate to me that she just flat-out isn't a good person, or really is too stupid to put two and two together. Like a friend who points and laughs while the schoolyard bully beats you up.
Had she been spending time in South Vietnam, posing with US soldiers but saying the exact same things, my opinion of her would be no different. Freedom of speech also means that you have to deal with the consequences of that speech; all it means is that the government can't legally take action simply because it doesn't like what you said. (Although that's now in doubt)