Don't befriend disbelievers

Let not the believers take the disbelievers as Auliyâ (supporters, helpers) instead of the believers, and whoever does that will never be helped by Allâh in any way, except if you indeed fear a danger from them. And Allâh warns you against Himself (His Punishment)[], and to Allâh is the final return.

Clarificaion
It is mentioned in Tafsir Al Jalalaeyen that this order was for the days before the hegemony of Islam and the order applies to every place where the Muslims are in minority in a land where unbelievers are in majority.