What is the ruling on revolting against an unjust ruler who has committed apostasy by aligning himself with disbelievers and showing enmity towards Muslims?

The doctrine of the People of the Sunnah and the Community (Ahl al-Sunnah wa al-Jama'ah) is to refrain from rebelling against an unjust ruler. This is not permissible unless the Muslims witness clear, unequivocal disbelief (kufr bawwah) for which they have proof. The consensus among the People of the Sunnah has settled on abandoning fighting during times of fitna (strife), enduring the injustice of leaders, and refraining from fighting them. As for allying with disbelievers (muwalat al-kuffar), it can be an act of disbelief (kufr) or a sin less than disbelief. Judging a specific person to be a disbeliever is not a light matter; rather, one must refer to well-established scholars regarding it.