No. Montenegro seceded peacefully from Serbia. Czechoslovakia dissolved into two parts peacefully (no seceding, but close enough). Finland seceded peacefully from Russia. Amongst others...
pretty much all of these cases were "crumbling/dissolution of empire" or similar. I.e. an opportunity presented by dramatic shift in force balance when dominating force is weakened and thus couldn't stop the process. It wasn't a result of a process legitimate according to the laws at that moment in that geography. And that is exactly my point (it wasn't about peacefulness - if you have obviously prevailing force, the things have good chances to happen peacefully, like in case of Crimea :). It is always about force. Laws, like always, follow the force and legitimaze the separation after the fact.
