[dubballey]

good Muslims fought good Muslims at the battle of the camel

Hadhrat Ali (raa) was a rightly guided one who is generally agreed to have been correct in his ijtehad over the issues related to it etc

also Hadhrat Abu Bakr (raa) fought those Muslim clans who refused to pay zakaat as apostates etc.


why its better for people like us not to try and derive ruling from hadith is because unlike the Ulema we only tend to know part of the story, so we tend to take a hadith that we read and fail to know its context or how it is to be understood etc, or how it interacts with all the other relevant Quran verses and hadiths etc.

also imam abu hanifah supporting the rebellion of Ibrahim and his brother against the Abbasid Khalifah (because the brothers wanted to implement shariah).
imam ibn taymiyyah fighting against Muslim secular tataris for their secularism.
imam hussein fighting against yazid.

there are recent examples also of such permissions granted by ulema to fight other 'Muslims'. some times the crime of the other party is so high that they become apostates. sometimes they stay within Islam yet permission is given to fight them.

as for self-defense: yes it is permitted to kill the offender without distinction of religion, age, gender (according to imam nawwawi as far as i can remb; other opinions on this I dont remb). This is an exceptional case obviously