The difficulty of accurate recognition constitutes one of the most serious sources of friction in war, by making things appear entirely different from what one had expected.

Kind-hearted people might of course think there was some ingenious way to disarm or defeat an enemy without too much bloodshed, and might imagine this is the true goal of the art of war. Pleasant as it sounds; it is a fallacy that must be exposed: War is such a dangerous business that the mistakes which come from kindness are the very worst.

Every age has its own kind of war, its own limiting conditions and its own peculiar preconceptions.

Friction is the only concept that more or less corresponds to the factors that distinguish real war from war on paper.

The world has a way of undermining complex plans. This is particularly true in fast moving environments. A fast moving environment can evolve more quickly than a complex plan can be adapted to it. By the time you have adapted, the target has changed.

Self-reliance is the best defence against the pressures of the moment.

To secure peace is to prepare for war.