In chapter 17 of Book 3 we see Clausewitz as prophet, and a remarkably accurate one at that. Writing about the Napoleonic wars, Clausewitz identified three trends that would characterize combat in the Second World War:
Guerrilla warfare – “The stubborn resistance of the Spaniards [to the French occupation of Spain] showed what can be accomplished by arming a people and through insurrection”.
Trading space for time – “the Russians showed us [during Napoleon's invasion in 1812] that one often attains one’s greatest strength in the heart of one’s own country, when the enemy’s offensive power is exhausted, and the defensive can then switch with enormous energy to the offensive”.
The nation-in-arms – “Prussia taught us in 1813 that rapid efforts can increase an army’s strength six times if we make use of a militia and…that the militia can fight as well in foreign countries as at home”.
Clausewitz concluded that because governments realized that the nation’s resources could be harnessed in war, “we cannot expect them to remain unused in future, whether the war is fought in self-defence or in order to satisfy intense ambition”.
Of the three trends, trading space for time and the nation-in-arms were cornerstones of Allied strategy and organization during WW2. As in 1812, when attacked by Nazi Germany the Soviets fell back into Russia’s vast country, allowing the Nazi advance to exhaust itself across great distance, in terrible weather and treacherous terrain, and in great urban and steppe battles. The British did the same in 1940, withdrawing behind the English Channel, as did the Americans and the British in the Pacific and Southeast Asia in 1941/42.
This approach allowed the Allies time to regroup, rebuild and rearm – through universal military conscription (the “nation-in-arms”) and turning the might of the industrial economy to all out war production. The harnessing of the nation’s labour, industry, finances and technology can be seen as an extension of the nation-in-arms concept – Clausewitz, writing at the dawn of the Industrial Revolution, doesn’t quite seem to have grasped the latent power of this aspect of the nation.
Meanwhile, guerrilla warfare played a useful supporting role, especially in Europe. It was used to wear down the enemy, and when the Allies went onto the offensive, to harry his defences and retreating forces. As a strategy it would come into its own after 1945 when fused with ideological struggle, mass political mobilization and modern weapons during Third World independence struggles, Cold War proxy conflicts and 21st century insurgencies.