﴿ إِنَّمَا يَنْهَىٰكُمُ ٱللَّهُ عَنِ ٱلَّذِينَ قَٰتَلُوكُمْ فِى ٱلدِّينِ وَأَخْرَجُوكُم مِّن دِيَٰرِكُمْ وَظَٰهَرُوا۟ عَلَىٰٓ إِخْرَاجِكُمْ أَن تَوَلَّوْهُمْ ۚ وَمَن يَتَوَلَّهُمْ فَأُو۟لَٰٓئِكَ هُمُ ٱلظَّٰلِمُونَ ﴾

“God only forbids you to turn in friendship towards such as fight against you because of [your] faith, and drive you forth from your homelands, or aid [others] in driving you forth: and as for those [from among you] who turn towards them in friendship; it is they, they who are truly wrongdoers!”

As far as justice and fair play are concerned, they will be given to everybody–whether friend or foe. But having friendships with those who are at war with one is not proper.