Book VI of On War is about von Clausewitz’s assertion of the pivotal role of defense in war. And so it is. To me however, the passages were echoes of Napoleon’s folly of invading Russia, vast and terrible, and the enduring lessons that von Clausewitz managed to distill from the frozen wasteland of the endless steppe. “The People’s War” rose in Spain against King Joseph Bonaparte and French occupation; led by juntas, the campesinos fought French soldiers with merciless savagery but it was waging war in Russia that had reduced Napoleon Bonaparte from a European Emperor, down again to a mere upstart Corsican general. A parvenu brigand on a continental scale.
No wonder Carl von Clausewitz was in awe of defense.
“If defense is the stronger form of war, yet has a negative object, it follows that it should be used only so long as weakness compels, and be abandoned as soon as we are strong enough to to pursue a positive object. When one has used defensive measures successfully, a more favorable balance of strength is usually created; thus the natural course in war is to begin defensively and end in attacking”
One of the anomalies of the crusade of Napoleon’s Grande Armee into the Russia of Tsar Alexander is that the Russians began in a position of numerical inferiority, something that had not happened at any other time except during the Mongol Yoke. Even Hitler’s massive onslaught of 150 Wehrmacht divisions hurled into the Soviet Union during Operation Barbarossa in 1941 did not enjoy the advantage in numbers held by Napoleon in 1812. Napoleon’s host had an almost mythic quality, reminiscent of the army of Great King Xerxes in The Persian Wars. Historian Alan Schom writes:
“Napoleon’s mighty force was phenomenal in size and strength as it continued its advance. They were marching by the thousands, the tens of thousands, the hundreds of thousands. It was incredible, it was fascinating, it was aew inspiring, but above all, it was terrifying. All Europe was trembling at the very thought of this massive Gallic-led horde, the likes of which had not been seen since the eighth century invasion of Europe by the Arabs and Berbers, and before that by Attila the Hun. Bavarians, Wurttemburgers, troops from Berg, Hesse-Darmstadt, Frankfurt, Nassau-Aremberg, Isenburg, Hohenzollern-Sigmaringen, Wurzberg, Saxony, Anhalt-Berburg, Schwarzburg-Sondershausen, Waldeck, Schaumburg-Lippe, Westphalia, Mecklenburg-Strelitz, Oldenburg, occupied Denmark, occupied Prussia, occupied Spain and Portugal, occupied Holland, occupied Switzerland, northern Italy, the occupied Papal States, Danzig and Illyria, tiny San Marino and the miniature principality of Liechtenstein….the marched hundreds of miles, some ultimately two thousand miles, because once more Napoleon Bonaparte had refused peace, because – obsessed beyond any rational thought – he demanded war and further conquest”
Tsar Alexander responded to the “Gallic horde” by trading space for time, evacuating Vitebsk and famously, Moscow, which was set to the torch. Alexander made use of the terrain, Russia’s vast and unforgiving span of earth to decimate the invaders whose lines of supply stretched vaporously thin.
Carl von Clausewitz wrote in chapter 3 of Book VI of On War:
“…But if for some reason, the attacker has to advance with divided forces – and problems of supply often leave him little choice – the defender obviously reaps the benefit of being able to attack a part of his opponent with his own full strength.
In strategy, the nature of flank and rear attacks on a theater of operations changes to a significant degree….
….3. Because of the greater areas involved in strategy, the effectiveness of the interior and therefore shorter lines is accentuated and forms an imortant counterbalance against concentric attacks.”
In Chapter 8 “Types of Resistance” , we see that Tsar Alexander’s retreat of scorched earth has provided a template for Clausewitz regarding the use of territorial space by armies on the defensive:
“….and therefore, two kinds of reactions are possible on the defending side, depending whether the attacker is to perish by the sword or by his own exertions.
….Indeed, the latter can essentially take place only where the retreat penetrates deeply into the interior of the country. It is in fact the only reason that can justify such a retreat and the great sacrifices it entails.”
The late, great, historian of old Russia, W. Bruce Lincoln, wrote of Napoleon’s predicament in smoldering Moscow:
“Throughout the fall of 1812, Napoleon waited in vain for Alexander’s peace proposals to arrive in the Kremlin. When none came, he made overtures of his own, but Alexander sent no reply. As the days stretched into weeks, Napoleon came to see that he, not Alexander, faced a truly desperate situation, for Russia’s armies grew stronger by the day while his own dwindled from desertions and the ravages of disease. He faced the hopeless prospect of wintering in Russia without adequate food, shelter, or supplies, surrounded by a people so hostile that they burned their grain rather than sell it for French gold. As winter approached, and as the Russian partisans stepped up their attacks on his rear, Napoleon saw that his line of communications, which relied upon a perilously vulnerable corps of couriers who raced from Paris to Moscow in fourteen days, must soon collapse.” 
As with Spain, in Russia Napoleon Bonaparte met with the “rage of the people” in addition to the Tsarist armies and Cossack hosts. And as in the case of Spain’s campesinos, the Russian muzhik was fired by religious zeal against the unholy invader. On Russia’s long suffering peasantry, it’s “dark people” still enthralled in serfdom then, J. Christopher Herold wrote of the popular reaction to the French:
“Alexander’s proclamation to his people, issued at the time of the French invasion, appealed to these deep seated feelings: Napoleon had come to destroy Russia; the entire nation must rise against ‘this Moloch’ and his ‘legions of slaves’. ‘Let us drive this plague of locusts out! Let us carry the Cross in our hearts and steel in our hands!’ The proclamation was read in all the churches, and the priests supplemented it with embellishments of their own. The comte de Segur, at this time an aide-de-camp to Napoleon, wrote: ‘They convinced these peasants we were a legion of devils commanded by the Antichrist, infernal spirits, horrible to look upon, and whose very touch defiled” 
Russia was well suited to all of Clausewitz’s conditions for which a general uprising would be effective; that is to say, Clausewitz determined his conditions for a general uprising from the Russian partisan experience against the French (and perhaps also, upon reflection, that of the Spanish guerrilla as well but Clausewitz saw Russia with his own eyes).
“The following are the only conditions under which a general uprising can be effective:
1. The war must be fought in the interior of the country.
2. It must not be decided by a single stroke.
3. The theater of operations must be fairly large.
4. The national character must be suited to that type of war.
5. The country must be rough and inaccessible because of mountains, or forests, marshes, or the local method of cultivation.”
Only five percent of the soldiery of the mighty Grand Armee that boldly marched into Imperial Russia with Napoleon made it out alive. Roughly the same percentage as of the Wehrmacht troops who had served under Field Marshal von Paulus at Stalingrad.
Despite the claims of abstract universalism put forth on behalf of On War by Clausewitzians, the great insights of General von Clausewitz – and they truly are great – are firmly rooted in time and place. Mother Russia casts a shadow long and deep.
 Schom, Alan. 1997. Napoleon Bonaparte. HarperCollins. NY.NY. 594.
 Lincoln, W. Bruce. 1981. The Romanovs: Autocrats of all the Russias. The Dial Press. NY.NY. 400.
 Herold, J. Christopher. 1963. The Age of Napoleon. Houghton Mifflin Company. Boston, Mass. 348