6 ideas
Irregular forces should behave like a gas, diffuse and everywhere, not like a body that holds a front. An army of Arabs in the desert could be 'an influence, a thing invulnerable, intangible, without front or back, drifting about like a gas.' An enemy trained to strike at concentrations then has nothing to hit.
Lawrence splits command into three factors. The algebraical covers the fixed quantities of space, time, and matter, the calculable ground an enemy must cover. The biological covers the living cost of men and material, which an irregular force can least afford to spend. The psychological covers the minds of one's own men, the enemy, and the watching population.
A regular army that must hold every square mile of a territory against an enemy who might appear anywhere needs a fortified post every four square miles, which the Turks could never garrison. Territory the rebels need not hold becomes a liability for the side that must hold it. Area times the cost of securing it defeats the occupier's resources, not battle.
The goal was to keep the Turkish garrison at Medina alive but useless, not to capture it. A static enemy, fed just enough by a railway that keeps getting cut but is never fully destroyed, ties down troops and supplies that would otherwise fight elsewhere. The rebels wrecked materiel, such as rails, bridges, and engines, rather than killing men, because Turkish equipment was scarcer than Turkish soldiers.
A rebellion can win with only 2 percent of the population as active fighters, provided 98 percent are passively sympathetic. The population's attitude is the real battlefield, because it supplies intelligence, shelter, and denial of information to the enemy. Lawrence treats propaganda, 'the printing press', as a main weapon of command for shaping the minds of the rebels, the enemy, and neutrals.
Lawrence lists the requirements for a rebellion to succeed. It needs an unassailable base, secure from attack and from the fear of attack. It needs a sophisticated alien enemy too few to occupy the whole area, plus a friendly population and rebels who have speed, endurance, and independence from supply lines. Given mobility, security, time, and doctrine, with rebels turning every subject into a friend, victory rests with the insurgents and the algebraical factors decide the end.