Controlling alliances through executing pressure
  In this paper the standard prisoners' dilemma is embedded in environmental conditions in which the interaction takes place. This provides a theoretical background to the analysis of the empirical studies which indicate that including additional factors when considering an alliance is very important. We show that such an approach, though theoretically simple, provides a powerful tool for suggesting successful strategies for forming, maintaining and withstanding a rival attack on an alliance, projecting an alliance possible success and determining which measures must be taken to maintain an alliance in a changing environment. It also provides insight into the possibility of preventing alliances in rivals. The relative simplicity of this framework means that the approach can be easily applied when the real life decisions are taken. 
L. A. Khodarinova, J. M. Binner, L. R. Fletcher, V. N. Kolokoltsov and   P. Whysall