Power Parity, Commitment to Change, and War

Article is about the proposition that power parity and commitment to change the status quo by a challenge are key variables.
Their theory applies both to major and minor powers.
An evaluation of the status quo determined whether a state would be willing to initiate a war.
In PT theory, focus is on opportunity (power parity) and willingness (negative evaluations of the status quo).
They argue that the probability of wars between contenders in local or international hierarchies increases significantly;
1) When power parity is achieved
2) When the challenger’s extraordinary build up exceeds that of the dominant power, revealing its willingness and commitment to change.
Multiple Hierarchies
Within the global system, there exist multiple regional systems, within each system, there is a status quo, a set of rules which affect the behavior of the system’s members.
They argue that extraordinary military buildups indicate disparate evaluations of the status quo, and that the relative size of the buildup indicates each actor’s relative commitment to either changing or defending that status quo.
Within each hierarchy the central condition for war is the same: parity and the challenger’s commitment to change.
In the absence of parity, there may even be a seeming absence of interaction between members of the local hierarchy because the local challenger is too weak to make credible demands from the local dominant power.
The relationship between war and dissatisfaction, given power parity, can be modeled as a step function where relations are peaceful until dissatisfaction reaches a critical level.
For discussion on the relationship between BoP and war see p.236.