In the US there are no laws that define penalties against sedition, so in effect there is no point at which a dissident crosses over into sedition in this country, at least not sedition that is punishable. And I know of no dissidents that have been thrown in prison lately over their dissidence, per se.
However, critics of the administration and other dissidents still have to face their fellow citizens and may rightfully come under attack for the stances they take. If they suffer criticism for what they say it is not tantamount to denying them the right to speak out. Speech may be free, but it still has consequences.
The problem for anti-war dissidents is that their stance is unpopular. Most people don't agree with them, so they are getting a lot of criticism. So, among other things, they bring up the Bill of Rights and cry that they have the right to say what they are saying.
Of course, they do, but in saying so they are just using a debating tactic to deflect people from the main issue, which is what they are saying about American policy, and whether what they are saying is right. It is just a tactic especially because criticism against them does not even come close to actually putting them at any real risk or discomfort, much less actually restricting their rights.
What impresses me about most of the anti-war dissidents these days is that they usually don't come across as people who are happy with America but just have some differences on a few issues. No, they talk like people who despise America and all of its institutions and its people, who see America as totally evil in every respect, who automatically assume that America acts on the basest motives that can be imagined. It is literally enough to make one wonder, "Gee, if these people are so angry and unhappy with America, why don't they just leave?" Which is why one is often prompted to ask that very question.
There is anti-war dissent that suggests to me that the dissent is born out of concern for one's country and one's fellow citizens. An example might be to say that war is a very bad idea because of the risk to military men and women and because the country might end up in a quagmire that is costly and risky to American lives, wealth, and political capital. It is also reasonable to wonder if Hussein actually has or will have the kind of weapons capablity that justifies this action. I think that there is enough of this sort of criticism to make one wonder if we would be doing the right thing to attack Iraq.
An example of anti-war dissent that suggests to me that the dissent is born out of hatred for America would be to say that America does not have the moral authority to act because, in effect, America is so evil, or America is acting out of hypocrisy, or America is just trying to get at Iraqi oil, or America just wants to spread its evil imperialist capitalist rule all over the face of the earth.
Do the people who spew this sort of thing really think that many Americans will be convinced by what they are saying? I realize that there is always a certain element on college campuses and the like that is attracted to such thinking, but can't they see that saying these things is just going to make most people mad at them?
When you get behind the reasons for why America is so evil in the eyes of these people it usually gets down to all the things that America had to do to survive the cold war and otherwise insure national security. In recounting such events the dissents always portray the US as acting purely out of bad motives, as if the other side in the cold war didn't exist, as if America has no enemies, or as if the Soviet Union and its allies were only motivated by goodness and light. Their view of history is so strongly biased against the US that it makes their hatred for the US obvious.
Perhaps for some of these dissidents it is that in being so successful America refutes the leftist ideals they hold so dear. Perhaps for others America stands as a Judeochristian bulwark that threatens to forever stymie any spread of Islam except in a watered down, secularized form. Perhaps for still others America upholds values of human rights, freedom, and democracy that they find threatening.