During history, an aggressive country seeks to force non-aggressive countries to made many
concessions based on military force. In our paper we discuss the situation that one aggressive
country is dissatisfied with its current position and try to obtain more concessions from a rival
country. To analyze this situation we use a game theory dynamic model in complete and
incomplete information. We analyze the countries behavior depending especially on
aggressive or non-aggressive strategies and also on battle power. In this context we found
conditions to obtain separating and pooling equilibriums for dynamic games in incomplete
information. Main result shows that countries behavior depends especially on war costs and
on country military power. There are many applications of these types of models, like in Israel
- Palestinian war, recent Russian- Georgian conflict or US defense policy.