Estimation of potential willingness of the state to use military force is an important part of analyzing international relations and preparing decisions in security sphere. This willingness characterizes the will (taking into account the desire, inclination, preparedness) of a certain state to use military force against another state in order to achieve its goals: suppression, controlling, subordinating and others. In our study, we showed that the existing methods for the numerical estimating this generalized indicator need to be improved. Estimating potential willingness of the state to use military force should be carried out with taking into account the uncertainty due to the fuzziness of the criteria, correlation interactions between them, and the ambiguity of the input data. To solve the problem, we developed a hierarchical structure of criteria, in which the input data are presented using fuzzy sets, the importance of the criteria is presented as a fuzzy measure, and the aggregating of partial estimations is performed using the Sugeno fuzzy integral. As a result, we calculated and discussed the estimations of 137 states, for which we were able to find the necessary initial data in open information sources.