The most common failure of imagination, in the politics of this world -- so common that it is not even restricted to people of the liberal political persuasion -- is the failure to grasp that things could always be worse. This cuts both ways on questions of war and peace. I am in favour of war when the reasonably foreseeable consequences of not fighting are even worse than those of the preferred mode of doing so. “No more war” is a prescription for tyranny and genocide: always has been and always will be.
On the other hand, I am in favour of not intervening, when the consequences of wading in would be overall worse. That was my argument against bombing our way to Belgrade, even though I agreed the Serbs were behaving monstrously. Likewise it is my argument against, say, bombing our way into Darfur -- attractive as that proposition might seem,
It must also be appreciated that all such decisions are messy, and necessarily messy, and horrible, and cannot be reduced to smug, trite slogans.