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

The heart of France lies between Brussels and Paris.

Everything in war is very simple, but the simplest thing is difficult. The difficulties accumulate and end by producing a kind of friction that is inconceivable unless one has experienced war. ... Countless minor incidents - the kind you can never really foresee - combine to lower the general level of performance, so that one always falls short of the intended goal.

Every combat is the bloody and destructive measuring of the strength of forces, physical and moral; whoever at the close has the greatest amount of both left is the conqueror.

All action takes place, so to speak, in a kind of twilight, which like a fog or moonlight, often tends to make things seem grotesque and larger than they really are.

Where execution is dominant, as it is in the individual events of a war whether great or small, then intellectual factors are reduced to a minimum.

If the leader is filled with high ambition and if he pursues his aims with audacity and strength of will, he will reach them in spite of all obstacles.