In futurology, a singleton is a hypothetical world order in which there is a single decision-making agency at the highest level, capable of exerting effective control over its domain, and permanently preventing both internal and external threats to its supremacy.
[1][2][3][4][5][6][7][8] According to Nick Bostrom, a singleton is an abstract concept that could be implemented in various ways:[9] a singleton could be democracy, a tyranny, a single dominant AI, a strong set of global norms that include effective provisions for their own enforcement, or even an alien overlord—its defining characteristic being simply that it is some form of agency that can solve all major global coordination problems.
Notably, a suitable singleton could solve world coordination problems that would not otherwise be solvable, opening up otherwise unavailable developmental trajectories for civilization.
[11] A singleton could set "very strict limitations on its own exercise of power (e.g. punctiliously confining itself to ensuring that certain treaty-specified international rules—or libertarian principles—are respected)".
[9] Furthermore, Bostrom suggests that a singleton could hold Darwinian evolutionary pressures in check, preventing agents interested only in reproduction from coming to dominate.