According to Wikipedia: World peace or peace on Earth is an ideal state of freedom, peace, and happiness among and within all nations and people. This ideal of world non-violence provides a basis for peoples and nations to willingly cooperate, either voluntarily or by virtue of a system of governance that prevents warfare. While different cultures, religions, philosophies, and organizations may have differing concepts about how such an ideal state might come about, they have in common this ideal of a cessation of all hostility amongst all humanity.
World peace could be established through religious or secular organizations that address to human rights, technology, education, engineering, medicine, or diplomacy used as an end to all forms of fighting. For example, since 1945, the United Nations and the 5 permanent members of its Security Council (the US, Russia, China, France, and the UK) have worked to resolve conflicts without war or declarations of war. However, nations have entered numerous military conflicts since that time.