Allah advises the believers not to make allies or friends with disbelivers instead of believers and making friendship with disbelivers is one of the clear evidences to justify the warrants of punishment.

 Allah advises the believers not to make allies or friends with disbelivers instead of believers and making friendship with disbelivers is one of the clear evidences to justify the warrants of punishment. 

"O you who have believed, do not take the disbelievers as allies instead of the believers. Do you wish to give Allāh against yourselves a clear evidence?"

Al Quran 4:144.