This chapter examines the light of the various inspirations for controlling the violence of war, namely religious, such as Christian pacifism; political, such as socialism and anarchism; and philosophical and ethical, such as passive resistance, with reference to recent world crises. The concept of pacifism may be as old as humanity itself, but a coherent study of pacifism only started in the 20th century. The appearance of pacifism is a disputable issue amongst pacifist scholars. Various factors can be identified as contributing to the tendency to pacifism in prior and present centuries. Christianity was the most important religion that played a momentous role in the development of pacifism. After the conversion of Constantine in 312 and the establishment of Christianity as the official religion of the Roman Empire in AD 313, the atmosphere of the Church changed on the subject of pacifism and the principle of non-resistance.