Competitive resource allocation in an attacker-defender game: When citizens become targets of being ingratiated

In the realm of counterterrorism, the role of citizens is crucial. In certain scenarios, such as during epidemics or political conflicts, citizens can become targets of being ingratiated between governments and terrorists. Notably, citizen targets possess distinct characteristics compared to other target types. This article centers on the competitive allocation of resources by the defender and the attacker on citizen targets. First, we incorporate utility functions into contest success functions to capture the subjective preferences of citizen targets. Subsequently, we construct a sequential game model of the defender and the attacker, considering their respective budget constraints. Furthermore, we examine how the investment effectiveness of both players impacts the likelihood of a successful attack, optimal resource allocations, and defense losses. Additionally, we model the relationship between the investment effectiveness and the inherent defense levels of citizen targets. Finally, we present a case study to demonstrate the practical applicability of our proposed model. The article's findings indicate that (i) achieving the optimal resource allocation should consider a combination of factors, including the effectiveness of defender and attacker investments, the inherent defense levels of citizen targets, and the population sizes of these targets and (ii) acknowledging the positive correlation between inherent defense levels and defense effectiveness, enhancing the inherent defense levels of citizen targets can substantially reduce defense losses. This article provides valuable methods and insights that can benefit government agencies worldwide in efficiently allocating resources to protect vulnerable citizen populations from terrorism risks.