War and politics

Entering the major work of Clausewitz bring you the theoretical elements to understand the war.
Remember the words of Trotsky: "You do not be interested in war, but war is interested in you!"
He had, he said, a military career "failed" because it remained of Staff officer, without ordering a troop. Clausewitz was present in Europe in the wars of the Revolution and the Empire (1793-1815) and then pacified Europe of the Holy Alliance (Westphalian system). He pulled out of weather resistant conclusions in trying to make true and eternally valid propositions to understand the essence of war. He tries to explain all wars (this "chameleon") by a general theory. War as a means (Ziel) submitted to the policy (Zweck) to obtain a reasonable goal in which the people are a danger: the rise to extremes by the eruption of passions.
Finally, we should not see a hawkish Clausewitz madman, although he loves war. For him, the war must be a reasonable course of action should be limited.
Enjoy reading!
PS: you can find elements of understanding in the book of Andrew in his masterful Beaufre (for clear and precise) introduction to the strategy. But also in Raymond Aron, think the war clausewitz