I also would like to note that one cannot appreciate the nature of Islamic expansion and treatment of non-Muslims without also studying Islamic history. Limiting oneself to reading the Koran simply will not suffice. Muhammed, himself, waged war against all who fell outside Islamic law and beliefs. He slew Jews for being Jews, Christians for being Christians, and anyone else who refused submitting to his will. When meeting an adversary in or off the field of battle, Muhammed typically gave three options to the "infidel":
3. Become a second-class citizen with little freedom or rights.
His successors continued his policy.
9.5: So when the sacred months have passed away, then slay the idolaters wherever you find them, and take them captives and besiege them and lie in wait for them in every ambush, then if they repent and keep up prayer and pay the poor-rate, leave their way free to them; surely Allah is Forgiving, Merciful.
17.16: And when We wish to destroy a town, We send Our commandment to the people of it who lead easy lives, but they transgress therein; thus the word proves true against it, so We destroy it with utter destruction.
17.58: And there is not a town but We will destroy it before the day of resurrection or chastise it with a severe chastisement; this is written in the Divine ordinance.
28.58: And how many a town have We destroyed which exulted in its means of subsistence, so these are their abodes, they have not been dwelt in after them except a little, and We are the inheritors,
28.59: And your Lord never destroyed the towns until He raised in their metropolis an apostle, reciting to them Our communications, and We never destroyed the towns except when their people were unjust.
63.4: And when you see them, their persons will please you, and If they speak, you will listen to their speech; (they are) as if they were big pieces of wood clad with garments; they think every cry to be against them. They are the enemy, therefore beware of them; may Allah destroy them, whence are they turned back?
40.22: That was because there came to them their apostles with clear arguments, but they rejected (them), therefore Allah destroyed them; surely He is Strong, Severe in retribution.
21.95: And it is binding on a town which We destroy that they shall not return.
46.25: Destroying everything by the command of its Lord, so they became such that naught could be seen except their dwellings. Thus do We reward the guilty people.
18.59: And (as for) these towns, We destroyed them when they acted unjustly, and We have appointed a time for their destruction.
9.30: And the Jews say: Uzair is the son of Allah; and the Christians say: The Messiah is the son of Allah; these are the words of their mouths; they imitate the saying of those who disbelieved before; may Allah destroy them; how they are turned away!
14.13: And those who disbelieved said to their apostles: We will most certainly drive you forth from our land, or else you shall come back into our religion. So their Lord revealed to them: Most certainly We will destroy the unjust.
5.51: O you who believe! do not take the Jews and the Christians for friends; they are friends of each other; and whoever amongst you takes them for a friend, then surely he is one of them; surely Allah does not guide the unjust people.
33.64: Surely Allah has cursed the unbelievers and has prepared for them a burning fire,
33.65: To abide therein for a long time; they shall not find a protector or a helper.
33.61:Cursed: wherever they are found they shall be seized and murdered, a (horrible) murdering.
2.257: Allah is the guardian of those who believe. He brings them out of the darkness into the light; and (as to) those who disbelieve, their guardians are Shaitans who take them out of the light into the darkness; they are the inmates of the fire, in it they shall abide.
3.151: We will cast terror into the hearts of those who disbelieve, because they set up with Allah that for which He has sent down no authority, and their abode is the fire, and evil is the abode of the unjust.
4.56: (As for) those who disbelieve in Our communications, We shall make them enter fire; so oft as their skins are thoroughly burned, We will change them for other skins, that they may taste the chastisement; surely Allah is Mighty, Wise.
7.41]:They shall have a bed of hell-fire and from above them coverings (of it); and thus do We reward the unjust.
9.35: On the day when it shall be heated in the fire of hell, then their foreheads and their sides and their backs shall be branded with it; this is what you hoarded up for yourselves, therefore taste what you hoarded.
9.113: It is not (fit) for the Prophet and those who believe that they should ask forgiveness for the polytheists, even though they should be near relatives, after it has become clear to them that they are inmates of the flaming fire.
27.90: And whoever brings evil, these shall be thrown down on their faces into the fire; shall you be rewarded (for) aught except what you did?
35.34: And (as for) those who disbelieve, for them is the fire of hell; it shall not be finished with them entirely so that they should die, nor shall the chastisement thereof be lightened to them: even thus do We retribute every ungrateful one.
41.28:That is the reward of the enemies of Allah-- the fire; for them therein shall be the house of long abiding; a reward for their denying Our communications.
48.13: And whoever does not believe in Allah and His Apostle, then surely We have prepared burning fire for the unbelievers.
76.4: Surely We have prepared for the unbelievers chains and shackles and a burning fire.
98.6:Surely those who disbelieve from among the followers of the Book and the polytheists shall be in the fire of hell, abiding therein; they are the worst of men.
4.101: And when you journey in the earth, there is no blame on you if you shorten the prayer, if you fear that those who disbelieve will cause you distress, surely the unbelievers are your open enemy.
4.140: And indeed He has revealed to you in the Book that when you hear Allah's communications disbelieved in and mocked at do not sit with them until they enter into some other discourse; surely then you would be like them; surely Allah will gather together the hypocrites and the unbelievers all in hell.
2.191: And slay them wherever ye catch them, and turn them out from where they have Turned you out; for tumult and oppression are worse than slaughter; but fight them not at the Sacred Mosque, unless they (first) fight you there; but if they fight you, slay them. Such is the reward of those who suppress faith.
4.76: Those who believe fight in the cause of Allah, and those who reject Faith Fight in the cause of Evil: So fight ye against the friends of Satan: feeble indeed is the cunning of Satan.