Elsewhere in this volume Charles Cockell points out that because of the confinement and necessary centralisation of fundamental life-supporting facilities to be expected in near-future extraterrestrial settlements, a revolution against a tyrannous government in such a settlement, analogous to the 1776 American Revolution , would be hazardous, if not impossible. But if such a revolution were nevertheless to be attempted, could there be future analogues to the US Revolutionary War ? We argue that so huge are the energies wielded by interplanetary cultures that any such war would be catastrophically lethal. An interplanetary "war of liberation" could not be waged without threatening the survival of the human species itself. It is therefore essential that an interplanetary political framework is established that guarantees colonial liberty without recourse to conflict.