Jihad against Oppression
Muslims are instructed to stop injustice and oppression. The following hadeeth clarifies the issue:
It is narrated by Anas that Allah's Apostle (صلى الله عليه و سلم) said, "Help your brother, whether he is an oppressor or he is an oppressed one. People asked, "O Allah's Apostle (صلى الله عليه و سلم)! It is all right to help him if he is oppressed, but how should we help him if he is an oppressor?" the Prophet (صلى الله عليه و سلم) said, "By preventing him from oppressing others." [Saheeh Bukhari]
Stopping oppression, whether commited by a Muslim or a non-Muslim is encouraged in Islam. This is clarified further with the following hadeeth:
It was narrated that Abu Bakr al-Siddeeq (رضي الله عنه) said: “O people, you recite this verse:
‘O you who believe! Take care of your ownselves. If you follow the (right) guidance [and enjoin what is right (Islamic Monotheism and all that Islam orders one to do) and forbid what is wrong (polytheism, disbelief and all that Islam has forbidden)] no hurt can come to you from those who are in error’ [Quran: Surah al-Maa’idah 5: Ayah 105]
I heard the Messenger of Allaah (صلى الله عليه و سلم) say, ‘When the people see an oppressor but they do not try to stop him, soon Allah will cause all of them to suffer punishment because of him.’” [Narrated by al-Tirmidhi, 2168; Abu Dawood, 4338; Ibn Maajah, 4005]. This hadeeth was classed as saheeh by al-Tirmidhi and Ibn Hibbaan, 1/540.
At-Tariq ibn Shihab (رضي الله عنه) reported: A man asked the Messenger of Allah (صلى الله عليه و سلم) as he put his foot in the stirrup, “What is the most virtuous struggle (jihad)?” The Prophet said, “A word of truth in front of a tyrannical ruler.” [Musnad Ahmad 18449]. This hadeeth was class as Sahih (authentic) according to An-Nawawi.