Below are some excerpts from the Koran from the excellent version, A Simple Koran.
Chapter 3, verse 28: Believers should not take unbelievers as friends in preference to other believers. Those who do this will have none of Allah's protection and will only have themselves as guards. Allah warns you to fear Him for all will return to Him.
Chapter 3, verse 118: Believers! Do not become friends with anyone except your own people. The unbelievers will not rest until they have corrupted you. They wish nothing but your ruin. Their hatred of you is made clear by their words, but even greater hatred is hidden within their hearts. We have made Our signs clear to you. Therefore, do your best to comprehend them.
Chapter 4, verse 89: They would have you become unbelievers like them so you will all be the same. Therefore, do not take any of them as friends until they have abandoned their homes to fight for Allah's cause. But if they turn back, find them and kill them wherever they are. Do not take any of them as a friend or a helper except those who seek asylum among your allies and those who come to you because their hearts have forbidden them from fighting against you or their own people.
Notice how clear and direct the language of the Koran is. It doesn't take a lot of "interpretation" and no amount of interpretation can make these nice passages.