The events of recent times are only correlationary evidence against non-democracies, but not actual causal relationships (at least not proven just by their existence). You can take another correlationary example in China where you would probably agree with me that there is little coup risk right now. Not saying democracies don't promote peace, but I am also saying I don't know if they do. Not something that is intuitive most likely. Also, the question arises with this on when a coup is justified. Sucession (which might be seen as some sort of overthrow) was justified by the founding fathers and anyone for self-determination will possibly be open to it.
That is not the point I was making with free trade- instead that the benefits of trade (and subsequent loss of those benefits upon a declaration of war [should trade be deterred which it almost always is]) between two countries increases the costs of war. Your example here might actually not promote peace if people realize they want democracy instead of communism, dictatorship, etc. and revolt. Arguably not a bad thing, but it isn't an argument against an overthrow or for domestic peace.
You said...
> ...in China where you would probably agree with me that there is little coup risk right now
I can't help but to believe that you're not really understanding who whole Arab Spring thing. This isn't about just the middle east. This is about the influence of the internet on the entire planet. This is quickly becoming a world where repressive governments can no longer hide from their misdeeds. And that's ESPECIALLY true of the granddaddy of them all...China. So no, I disagree strongly with your assumption. I would say the Chinese dictators (and ANY other dictators left) are not sleeping easy. And they are attempting to tighten their grip on the internet. But the nature of the technology is such that they will always fail. All of them are just a single bad news story...a girl being murdered in the streets...a young boy mutilated by the police...away from extinction. This dictator stampede is already underway. Just read the news.
I can't help but think we're getting lost in the rhetoric here. Allow me to ask you a simple question....which is better? Dictatorship or democracy?
gary