Popular idea of a security community assumes that war among members of the community is (i) unthinkable, and (ii) that states do not prepare for such an eventuality. In its original formulation lack of border fortifications (a la Maginot line) was mentioned as a strong signal indicating that European states do not prepare for eventual war with their neighbors.
Given the post-World War II. war military doctrine and practice, border fortresses are however irrelevant. Thus, missing fortresses says nothing about the existence of a security community.
It makes sense, however, to look at the ability of a state to prevent a breakthrough which enables rapid and relatively costless victory for an aggressor. Therefore, we should ask, if the creation of a security community has led to systemic changes regarding this issue.
Is it true that at least some otherwise powerful members of a security community lost the ability to thwart breakthrough? And is it true that smaller members of the community field armies that would have a very small chance at delaying breakthrough? Affirmative responses would support the claim that members of the security community do not build armies to deter their neighbors. Negative answers would indicate that there is a mismatch between pacifist discourse and actual military buildup.
These questions, however, cannot be resolved easily. 1) even outside of a security community, actual wars are rare, 2) given that the definition of a security community presupposes the absence of actual war, we are talking about counterfactual scenarios. To solve this problem, we run iterated simulations of breakthrough attempts among European (and some non-European) states for different periods (before and after the security community emerged as well as before, during and after the Cold war).
We base our simulation on a set of alternative specifications of S. Biddle's formal model of military dynamics (filled with actual data on armies strength and posture) to check for robustness of our results.
We further adapted the model to provide probabilistic predictions, which enabled us to compute average time to achieve a breakthrough and average odds of a breakthrough. Comparison of the average territorial gains and odds of a breakthrough among members and nonmembers of the security community in different years solves our research questions.