War is not a continuation of politics, war is the measure used when politics has broken down. We can't work out our differences, so now we will fight them out. Where politics comes back into play, is when the winner of that war, allows the occupied nation to take a role in the occupation and or post war governing of the defeated nation.
I guess that's one way to look at it. I disagree 100%.
http://www.clausewitz.com/readings/OnWar1873/Bk8ch06.html
We know, certainly, that war is only called forth through the political intercourse of Governments and nations; but in general it is supposed that such intercourse is broken off by war, and that a totally different state of things ensues, subject to no laws but its own.
We maintain, on the contrary: that war is nothing but a continuation of political intercourse, with a mixture of other means. We say, mixed with other means, in order thereby to maintain at the same time that this political intercourse does not cease by the war itself, is not changed into something quite different, but that, in its essence, it continues to exist, whatever may be the form of the means which it uses, and that the chief lines on which the events of the war progress, and to which they are attached, are only the general features of policy which run all through the war until peace takes place. And how can we conceive it to be otherwise? Does the cessation of diplomatic notes stop the political relations between different nations and Governments? Is not war merely another kind of writing and language for political thoughts? It has certainly a grammar of its own, but its logic is not peculiar to itself.
Accordingly, war can never be separated from political intercourse, and if, in the consideration of the matter, this is done in any way, all the threads of the different relations are, to a certain extent, broken, and we have before us a senseless thing without an object.