Ruling on declaring Muslims ruled by someone who does not apply Shari`ah to be Kafirs

A: It is not permissible to declare Muslims ruled by a regime ruling with other than Allah's Shari`ah as Kafirs as long as their hearts are filled with Iman (Faith) in Allah and His Messenger and they observe whatever Allah has prescribed for them as much as they can, and hate whatever diverges from the purified Islamic Shari`ah. However, the great sin rests with whoever promotes, agrees to and approves of such laws in Muslim countries. We seek refuge in Allah from betrayal and oppression. (Part No. 1; Page No. 423) May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.