Nicolay

"Historical judgement of war is subject to an inflexible law, either very imperfectly understood or very constantly lost sight of.  Military writers love to fight over the campaigns of history exclusively by the rules of the professional chess board, always subordinating, often totally ignoring, the element of politics.  This is a radical error.  Every war is begun, dominated, and ended by political considerations.  Without a nation, without a government, without money or credit, without popular enthusiasm which furnishes volunteers, or public support which endures conscription, there could be no Army and no war...War and politics, campaign and statecraft, are Siamese Twins, inseparable and interdependent; and to talk of military operations without the direction and interference of an administration is as absurd as to plan a campaign without recruits, pay or rations."
-Nicolay and Hay, Abraham Lincoln: A History