Firstly that's not the "Koran" that says but it's a Prophetic report, meaning something the Prophet said. Secondly, it just says that Muslims will fight against the Jews (a prophecy), it doesn't say that Muslims *ought* to fight against the Jews for no reason. Thirdly, the "Koran" itself and Prophetic reports make it absolutely clear that the justification for war isn't unbelief but rather waging war, that's why all available evidence indicates that pre-modern Muslim jurists held the Prophetic warning against killing civilians seriously, even in times of war, and this is clear from the dozens of narrations to this effect, * Women: ʿAbd Allāh b. ʿUmar said, ‘A woman was found slain in one of the expeditions. Upon this the Messenger of God ﷺ forbade the killing of women and children’. [Narrated by Muslim in al-Saḥīḥ: Kitāb al-jihād wa al-siyar, chapter: ‘The Unlawfulness of Killing Women and Children during War’, 3:1364 §1744;] * Children: Aswad b. Sarīʿ said, ‘We were once in a battle and gained the upper hand and killed many of the pagans, including some children. News of this reached the Messenger of God ﷺ and he said, “What is wrong with some people that they went so far as to kill children? Beware! Do not kill children at all! Beware! Do not kill children at all!”’ [Narrated by al-Nasāʾī in al-Sunan al-kubrā: Kitāb al-siyar, chapter: ‘The Prohibition of Killing the Children of the Pagans’, 5:184 §8616; al-Dārimī in al-Sunan, 2:294 §2463; al-Ḥākim in al-Mustadrak, 2:133-134 §§2566-2567; and al-Ṭabarānī in al-Muʿjam al-kabīr, 1:284.] * The Elderly: Imam al-Bayhaqī narrated a hadith from ʿAlī, that when the Prophet ﷺ would dispatch an army, he would advise them, ‘Do not kill a young boy, a woman or an old man. Do not cause fountains to dry up and do not destroy any trees, except those which cause hindrance during war. Mutilate neither a human nor an animal, and do not break a promise or breach a trust’. [Narrated by al-Bayhaqī in al-Sunan al-Kubrā, 9:90 §17934.] * Religious leaders of non-Muslims (e.g. Monks): Imam Aḥmad b. Ḥanbal quoted Ibn ʿAbbās who said that the Prophet ﷺ would issue clear instructions when dispatching an army to go into battle. He ﷺ would say, ‘Break no promise, steal not from the spoils of war and do not mutilate bodies or slay children or monks’. [Narrated by Aḥmad b. Ḥanbal in al-Musnad, 5:358 §2728.] * Non-Muslim Traders and Farmers (who do not wage war): Imam Ibn Abī Shayba and Imam al-Bayhaqī narrated on the authority of Jābir b. ʿAbd Allāh who said, ‘They [the Muslim soldiers] did not kill the merchants amongst the pagans’. [Narrated by Ibn Abī Shayba in al-Muṣannaf, 6:484 §33129; al-Bayhaqī in al-Sunan al-kubrā, 9:91 §17939; and cited by Ibn Ādam al-Qurashī in al-Kharāj, 1:52 §133.] The famous encyclopedic scholar Ibn Qudāma al-Maqdisī stated, ‘As for the farmer who is a non-combatant, he should not be killed, because it was narrated from ʿUmar b. al-Khaṭṭāb that he said, “Fear God regarding the farmers who do not wage war against you”.’ [Ibn Qudāma al-Maqdisī, al-Mughnī, 9:251.] * Non-Muslim Service Personnel: Rabāḥ b. Rabīḥ said, ‘We were with the Messenger of God ﷺ in one of the battle expeditions, when he saw some people gathered around something. He sent a man out, saying, “Go and see what they are gathering around”. The man returned and informed him, saying, “They are gathering around a slain woman”. The Prophet ﷺ said, “She was not amongst those who fight!” At the head of the group was Khālid b. Walīd, so the Prophet sent a man to go and inform Khālid: “Neither an [idolatrous] woman nor a hired servant should be killed”.’ [In one report:] ‘Do not kill children or hired servants’. [Narrated by Abū Dāwūd in al-Sunan: Kitāb al-jihād, chapter: ‘The Killing of Women’, 3:53 §2669; Ibn Mājah in al-Sunan: Kitāb al-jihād [The Book of Martial Jihad], 2:948 §2842.] * Non-Muslim messengers and ambassadors: ʿAbd Allāh b. Masʿūd said, ‘It is an established Sunna (i.e. Prophetic precedent) that ambassadors are not to be fought’. [Narrated by Aḥmad b. Ḥanbal in al-Musnad, 1:390 §3708.] * Any non-combatants: Civilians in general, examples of which are above, are not to be targeted even in war. In a report, Abū Shurayh narrated that Prophet ﷺ said, “Verily, the most tyrannical of people to God the Exalted is he who kills those who did not fight him.” [Narrated by Aḥmad b. Ḥanbal in al-Musnad, §15943.] Not only that, but Muslims are obliged to go and fight for the protection of their fellow non-Muslim 'citizens' (which includes Jews & Christians). This may sound as strange for some, but that is in reality what classical Muslim jurists ruled, thus the Andalusian jurist Ibn Ḥazm (d.1064) wrote in his book *Marātib al-ijmāʿ* (which is about detailing the points on which there is a consensus in Islām), > ‘It is obligatory for us to go out and wage war against them [who aggress against the non-Muslim citizens of an Islamic state] with military might, **even though we may die in the process**’. [Quoted in al-Qarāfī, al-Furūq, 3:14-15.] Shihāb al-Dīn al-Qarāfī, the famous Mālikī jurist, wrote in his book al-Furūq about the rights of non-Muslim citizens: > The treaty of protection that we have with non-Muslims establishes certain rights that they have upon us because they live in proximity to us and are under our protection and care and the care of God and the Messenger of God and the religion of Islam. So whoever transgresses against them, **even if by an evil word or through backbiting**, ***has neglected the guarantee of God, His Messenger and the religion of Islam.*** [al-Qarāfī, al-Furūq, 3:14-15.]