The use of weapons of mass destruction has been a burner issue in most world conferences including the UN annual summits of the Security Council and even in the meeting of the G-8 and G-20 countries. The armament and even the Non- proliferation treaties have been used to cut down the usage and the manufacture of nuclear weapons commonly called the weapons of mass destruction. However, as long as we try to fight the current challenge facing the world security today, we must not forget the past as history may repeat itself. This report seeks to look at the Second World War as the first instance in the use of the nuclear weapons. The focus in this paper is on the bombings of Hiroshima and Nagasaki cities of Japan. Besides, the write up also addresses the effects of this incident to the Japanese and the world at large. The future use of weapons of such a devastating nature and how this war changed the world history are also key in this report.