  We are investigating a paradigm of instability in coalition forming among
countries, which indeed is intrinsic to any collection of individual groups or
other social aggregations. Coalitions among countries are formed by the
respective attraction or repulsion caused by the historical bond propensities
between the countries, which produced an intricate circuit of bilateral bonds.
Contradictory associations into coalitions occur due to the independent
evolution of the bonds. Those coalitions tend to be unstable and break down
frequently. The model extends some features of the physical theory of Spin
Glasses. Within the frame of this model, the instability is viewed as a
consequence of decentralized maximization processes searching for the best
coalition allocations. In contrast to the existing literature, a rational
instability is found to result from forecast rationality of countries. Using a
general theoretical framework allowing to analyze the countries' decision
making in coalition forming, we feature a system where stability can eventually
be achieved as a result of the maximization processes. We provide a formal
implementation of the maximization principles and illustrate it in the
multi-thread simulation of the coalition forming. The results shed a new light
on the prospect of searches for the best coalition allocations in the networks
of social, political or economical entities.
