From a conversation I had last spring with Scott Weber, who heads Interpeace.org:
“The calm following certain decisive war victories is dangerous as it masks the factors that can fuel future violent conflict and civil war in the future.”
Scott M. Weber, Director-General, Interpeace
On the other side, I have also heard people argue, persuasively if not popularly, the following viewpoint:
There is some irony in recognizing that, while negotiations bring a just process that can be better defended and that people can buy into, in general, after a "decisive victory" of one side, peace is more sustainable than in a "negotiated peace", which may be harder to sustain…