Fighting is prescribed in Islam in 3 instances

1- In self defence,

All divine religion has permitted fighting in self defence, which is a principle adopted universally in civil law. As the Qua'an states: "And fight in God's cause those who fight you, and do not transgress, surely God doesnot love transgressors" (Surah 2 verse 190).

2- War in the cause of God,

Jihad is clearly defined in Qur'an as meaning to fight those who sway the Muslim away from his religion or prevent him from adhering to it. This fight is waged solely for freedom to call men to God and to his religion. As the Qur'an states: "And fight them until there is no more persecution and the religion prescribed by God is fully established" (surah 8 verse 39).

3- Defence of the oppressed,

It is a religious obligation to defend those persecuted for their religious conciction-be they Muslims or non-muslims. It is this principle of freedom of conviction which is also a principle adopted in modern democratic constituations. The Qur'an sanctions the use of the sword under certain circumstances in the cause of religion-and not for Islam sxclusively, when a house of worship is in danger, be it chrestian, jewish, hindu, buddhist or muslim, a muslim is enjoyed to shed his blood to save it from destruction, as The Qur'an states: "Permission to fight back is given to those who have been oppressed, and surely is Most Powerful to bring their victory * Those who were expelled from their homes unjustly, only that they say:" Our Lord is God". Had God not repelled one people by means of another, there would have been destroyed cloisters, monasteries, temples, and mosques, in which the name of God is much mentioned. And surely God will help those who stand in his cause; surely God is All-Powerful, Almighty". (Surah 22 verse 39-40).