Surah 2. Al-Baqara, Ayah 190

This and the following verses lay down unequivocally that only self-defence (in the widest sense of the word) makes war permissible for Muslims. Most of the commentators agree in that the expression la ta'tadu signifies, in this context, "do not commit aggression"; while by al-mu'tadin "those who commit aggression" are meant. The defensive character of a fight "in God's cause" - that is, in the cause of the ethical principles ordained by God - is, moreover, self-evident in the reference to "those who wage war against you", and has been still further clarified in 22:39 - "permission [to fight] is given to those against whom war is being wrongfully waged" - which, according to all available Traditions, constitutes the earliest (and therefore fundamental) Qur'anic reference to the question of jihad, or holy war (see Tabari and Ibn Kathir in their commentaries on 22:39 ). That this early, fundamental principle of self-defence as the only possible justification of war has been maintained throughout the Qur'an is evident from 60:8 , as well as from the concluding sentence of 4:91 , both of which belong to a later period than the above verse.

 “Do not exceed the limits” refers to Islamic warfare guidelines set by the Prophet. In an authentic saying collected by Abu Dawûd, he (ﷺ) is reported to have instructed the Muslim army, “Depart in the Name of Allah and with His help—following the way of the Messenger of Allah. Do not kill an old man, a child, or a woman. Do not mutilate dead bodies of the enemy. Be gracious and courteous, for Allah loves those who act with grace.” The Prophet (ﷺ) also says, “Do not wish to meet your enemy in battle but always pray for well-being. If fighting is a must, then be steadfast.”

War is only permissible in self-defence, and under well-defined limits. When undertaken, it must be pushed with vigour, but not relentlessly, but only to restore peace and freedom for the worship of God. In any case strict limits must not be transgressed: women, children, old and infirm men should not be molested, nor trees and crops cut down, nor peace withheld when the enemy comes to terms.