It is undeniable fact that the war has become an integral part of humanhistory. In contemporary time, as it was in the past, international powerswaging wars against week nations in spite of their global peace discourse.Despite of this reality it is claimed that Islam does not allow war exceptunder extreme necessities such as to defend the country against occupationpowers. This type of claims weakens Muslims resistance against enemy.For the vital importance of the subject the researchers tried to exploretheory of war in Islam; its meaning, its legality, and its ethical dimension.In order to achieve this goal the researchers focused on related holy textsfrom Qur’an and Sunnah.