Religion has often been a useful pretext for internal or international conflicts. On the one hand, the protection of religious minorities and communities provides an excuse for intervention, often foreign intervention. On the other hand, religious discrimination and intolerance are used to encourage violence, although they may be masked by other aims.
The most notable religious war in western civilization were the Crusades and the wars following the Reformation. The idea of crusade is one of three Christian attitudes toward war, alongside pacifism and the idea of just war. The crusade had four characteristics: holy cause, belief in divine guidance and aid, godly crusaders and ungodly enemies, and unsparing prosecution. The laws of Islam provided for Jihad, or "Holy War", and thus assisted the spread of that faith.
Although most of the major faiths stand for peace, religious justifications are put forward for militarism. Thus attempts are made to equate the defence of a particular economic and social system with that of "Western/Christian civilization". Certain repressive governments define themselves as "Christian" and profess to be defending "Christian values". Governments or groups in Islamic countries continue to declare Jihad.