It is an important task to determine the degree of threat of threats in military applications and in the war environment. Small mistakes that can be made during the threat evaluation phase can cause great loss of life and property. Mistakes that can be made at this stage can lead to serious consequences that are difficult to compensate. For this reason, it is of great importance to accurately calculate the threat degree of the detected aircraft. For this purpose, computer decision support systems provide significant support to the operators in the decision-making process in order to increase the cognitive ability of the operator and to implement the decisions taken quickly. In this study, a decision support system is designed to contribute to the decision-making processes of the operators. In order to perform calculations in the decision support system; A threat assessment interface was created with the help of C# programming language using Microsoft Visual Studio. In the study, calculations were made using the speed, altitude and distance parameters of an aircraft classified as a threat to be used in the threat evaluation and weapon assignment interface. Fuzzy logic method was used to calculate the threat degree.