What happens after an empire is displaced? When an imperial construct is removed, such as the British Raj or the control of the French Caribbean colonies, what fills the vacuum? In the real world, there are various forms of action, from a careful, gradual absence (the British withdrawal from India) to a devastating collapse, with violence accompanying partition (the fall of the Soviet Union). Historically, the removal of an imperium has more often been a gradual process; a new structure of postcolonial governance has usually been able to fill as much as it can or wants of the vacated postimperial matrix. This new growth has many names. It may reclaim an older nationality or proclaim itself reborn in a different guise. It may become part of a new association or may, as illustrated by events in the demise of the Soviet Union, devolve into small units of varying culture. But in the realm of fiction, and especially of SF, transition between the old regime and the new is often more distinct and abrupt, the requirements of the narrative overriding the realities of slow political exactitude, demanding some more immediate, alternative replacement – an instant fabrication. Political forms can alter radically and without even a partial precedent, especially in the avant-garde of SF.

Traditionally, the genre still embraces a certain strain of realism, as the old centre expires and is replaced by something which incorporates a predictable political decay, such as the gradual reformation of the ‘old’ USA into the economic despond of Philip K. Dick's Do Androids Dream of Electric Sheep? (1968) or Isaac Asimov's Foundation and Empire (1952). Occasionally the absence of one empire is replaced by some dynamic neo-empire or imperial metaphor, such as the children's developing tyranny in Arthur C. Clarke's Childhood's End (1953) or the rise of the Fremen in Frank Herbert's Dune Messiah (1969). Occasionally an author will experiment with a completely new concept, offering the reader a new alternative such as Banks's ‘Culture’.

There is little room in SF texts for a political hiatus of any kind, as the genre's dynamic demands some explicit alternative, either powerful (neoempire) or enfeebled (political decay), against which to highlight their futuristic science and technology.