Abstract: War is costly and it consumes the taste of blood of fighters who are negaged in war and of innocent citizens. It temporarily satisfy the winners and suffers the lossers, but in long-run, both parties suffer. Rationality or miscalculation and misperception always play key roles in determining the potential outcome of wars by the experts and leaders. States’ leaders, sometimes, do not calculate the overall impact of war in the internal affairs of the states except their winning in elections through mechanism. Findings show that relative power is often not a good predictor of outcomes of Wars. Our research found and conclude that war is mostly irrational (that means miscalculation and misperception matter) when it is considered from the initiator point of view, but it would be rational when States want to defend themselves against other threat(s), especially in destructive conflicts, but it should follow the international war rules and regulations.