There is a long-running discussion, taking place in various forums on the Internet and elsewhere, that has as it's core question "When is it time for revolution?"
This isn't an easy question to answer with any sort of certainty. I've participated in The Discussion more than once, and I've yet to see an answer to the question I find satisfactory. It seems there are just too many ifs, ands and buts. It doesn't seem possible to draw a line and say "Anything over this means war." There are simply too many variables, ranging from your own willingness to die for a cause, through concern on the impact your decision may have on your family, to a simple uncertainty that the way you interpret certain events is "correct".
The Discussion is once again going on, this time at Kim du Toit's Nation of Riflemen blog. This is one of the best and most annotated versions of The Discussion I can remember, which is why I'm noting it here. It's a lot to read, and getting longer by the minute. There are also a lot of excellent links to follow, some of which lead to scholarly papers that will take you hours to read and mentally digest.
However, it's an important topic, and one that may be becoming more, rather than less, topical. Visit Kim's place and take part, or lurk if that's what you prefer. But you should read this--it's important.
Edit, 6/15/2005: Kim du Toit's thoughts on "when" are here.