Al-Fasad is a word referencing 'polytheist criminals'. Non-Muslims are by Islamic doctrinal definition pagans and polytheists. Christians are polytheists since Orthodox Christ worship supports the 'Trinity'. Jews are polytheists since they have conflated other idols [Yahweh] with Allah.
98-6: Verily, those who [despite all evidence] are bent on denying the truth - [be they] from among the followers of earlier revelation or from among those who ascribe divinity to aught beside God - will find themselves in the fire of hell, therein to abide: they are the worst of all creatures. 98:6
Al-Fasad is a serious category of criminality within Islamic theology. It is the same as being a Fujjar or common criminal, or a Mujrimun, a disbelieving polytheist sinner.
11-116 If only there had been among the generations before you, persons having wisdom, prohibiting (others) from Al-Fasad (disbelief, polytheism, and all kinds of crimes and sins) in the earth, except a few of those whom We saved from among them. Those who did wrong pursued the enjoyment of good things of (this worldly) life, and were Mujrimun (criminals, disbelievers in Allah, polytheists, sinners, etc.). [Hilali-Khan]
The Koran is clear that militant Al-Fasad criminals must be killed. Polytheists who accept Islam can be tolerated since they are taxed and can work for the benefit of the Moslem state and its rulers. But Mujrimun and Al-Fasad who fight back are to be exterminated:
5-33 The recompense of those who wage war against Allah and His Messenger and do mischief in the land is only that they shall be killed or crucified or their hands and their feet be cut off on the opposite sides, or be exiled from the land. That is their disgrace in this world, and a great torment is theirs in the Hereafter.
Sura 5-33 is preceded by the oft-quoted phrase that murder is illegal. But this is only true if a Moslem kills a Moslem. If you are an Al-Fasad you can certainly be murdered:
5-32 Because of that We ordained for the Children of Israel that if anyone killed a person not in retaliation of murder, or (and) to spread mischief in the land - it would be as if he killed all mankind, and if anyone saved a life, it would be as if he saved the life of all mankind. And indeed, there came to them Our Messengers with clear proofs, evidences, and signs, even then after that many of them continued to exceed the limits (e.g. by doing oppression unjustly and exceeding beyond the limits set by Allah by committing the major sins) in the land!
Sura 5-33 thus qualifies 5-32. As a Muslim you may kill someone in retaliation for a murder [“..if anyone killed a person not in retaliation of murder..] and importantly if you spread mischief in the land you can be obviously be killed since you are a criminal polytheist. 5-32 portrays the rejection by the Jews [Al-Fasad and Mujrimun] of Allah's 'signs'. As such they can be killed since be default they are spreading mischief.
2-27 Those who break Allah's Covenant after ratifying it, and sever what Allah has ordered to be joined (as regards Allah's Religion of Islamic Monotheism, and to practise its legal laws on the earth and also as regards keeping good relations with kith and kin), and do mischief on earth, it is they who are the losers.
The 'losers' will go to hell of course.
13-25 And those who break the Covenant of Allah, after its ratification, and sever that which Allah has commanded to be joined (i.e. they sever the bond of kinship and are not good to their relatives), and work mischief in the land, on them is the curse (i.e. they will be far away from Allah's Mercy); And for them is the unhappy (evil) home (i.e. Hell).
The entire point of identifying Al-Fasad and Mufsidun is to warn anyone, including wavering Moslems, of embracing pagan polytheism. If you are a polytheist you are going to either be killed by the Allah-cult, or go to hell. The main theme is that Islam as a political-social project can only remain strong if polytheism is wiped out within Islamic lands and the pagans are made to feel inferior and hunted.
16-88 Those who disbelieved and hinder (men) from the Path of Allah, for them We will add torment over the torment; because they used to spread corruption [by disobeying Allah themselves, as well as ordering others (mankind) to do so].
The objective of the Mohammed cult is complete control over society and indeed the globe in the form of a unified church-state complex. Fitnah or unending wars against the polytheists is assured until this is accomplished:
8-73 And those who disbelieve are allies to one another, (and) if you (Muslims of the whole world collectively) do not do so (i.e. become allies, as one united block with one Khalifah - chief Muslim ruler for the whole Muslim world to make victorious Allah's Religion of Islamic Monotheism), there will be Fitnah (wars, battles, polytheism, etc.) and oppression on earth, and a great mischief and corruption (appearance of polytheism).
Al-Fasad and the criminal polytheists must be fought until a unified Caliphate is established across the globe. The Koran makes this clear and makes this an objective and imperative. The categorization of polytheists as criminals, does not offer much in the way of tolerance towards non-Muslims.