Nuclear Weapons Are Harmful for Societal Peace and Progress
Everybody these days has heard about the term 'nuclear weaponry' from the media. Almost every big and powerful country possesses nuclear weapons and they say the weapons are for their own protection. But are nuclear weapons an aid to progress or a bane to world peace? In this paper I try to argue that nuclear weapons are an impediment to human progress and a bane to societal harmony, peace and prosperity.
First of all, nuclear weapons have a history of hindering peaceful life and acting as a detriment to progress by causing demolition and destruction of advances made in the fields of construction, infrastructure, arts and science. We can take the well known example namely the nuclear bombing of Hiroshima and Nagasaki in Japan during the Second World War, in 1945.  This caused great harm to the people inhabiting the island nation of Japan and though it was intended to show the military might of a powerful nation, it caused untold sufferings to the people of Japan. It acted as an impediment to the progress that Japan had achieved for several decades by reversing constructive effects and causing destructive and harmful effects.
Thus, by virtue of causing human suffering, nuclear weapons have a history of getting used for purposes of destruction. If we believe in 'history repeats itself'  then the day is not far off when one day we might find ourselves being bombarded by the effects of nuclear weapons. In order to protect ourselves and the interests of our future generations, we must take steps to ban or reduce the amount of nuclear stock piles accumulated by countries all over the world. This way, we can be sure our continuing lineage can be safe from a possible nuclear holocaust or catastrophe.
The second point against the maintenance and use of nuclear weapons is that the use of nuclear weapons causes mutations in the human genes. The use of such weapons can cause our future generations get exposed to harmful radiations accruing from the nuclear blasts. This can cause several harmful effects in humans, including diseases like cancer. These health problems are not what we are striving to achieve with the advances in health care industry. Harmful gamma and neutron radiation may expose human's genetic material and cause bad effects that were hitherto not measured or documented, such as genetic mutations. 
The third point as to why I oppose the existence or development of nuclear weapons is that, it could be easy for these weapons to fall into the wrong hands. Hypothetically, in an era of political unrest and chaos, the bad elements among the people such as terrorists could get their hands on these pieces of weaponry. This can possibly result in thousands of innocent people getting killed or maimed due to the deleterious effects of the use of the nuclear weapons. It is horrifying to think what would happen, if the 'wrong hands' get hold of nuclear weapons and their controls. A high amount of security costs is also required as a capital outlay for the country developing nuclear weapons, in order to protect these weapons from ever getting into the wrong hands with malicious intentions. We may want to recall the high costs of securing our borders and efforts undertaken by the Transportation Security Administration (TSA) due to the aftermath of events like 9/11. 
The fourth point regarding my belief that opposing nuclear weapons is just is because, the money spent on developing and maintaining a nuclear arsenal is better spent on other peaceful efforts by the country trying to play one-up with other weapon-wielding countries. There is a huge amount of progress that can be made in the areas of green energy, renewable energy, sustainable organic farming, improving infrastructure like roads, highways, electricity, etc. in the case of developing countries. But some countries seem to invest a lot of their annual budget moneys for ostensible nuclear defence purposes. A major portion of the moneys laid out for defence are taken from an annual budget that could be constructively used for other developmental purposes. By allocating large sums of money for defence and nuclear weapons development, the countries which promote development of nuclear weapons are denying investments and development of other fields such as infrastructure development, education, healthcare, science, space research, etc.
Lastly, it can be too easy for World War III to start, and human life as we know of, can get wiped out in a huge nuclear free-for-all where everybody tries to threaten and destroy everyone else. The fallout for such a war can be devastating for human kind itself. There exists the very real possibility that all human life could end with a nuclear catastrophic free-for-all started by some nuclear armed nation somewhere in the world.
In conclusion, nuclear energy is something that we need to use, direct and channel for peaceful purposes only, like for the generation of electricity. If we start and maintain an arms race with nuclear weapons in our arsenal, almost every country on earth will want nuclear weapons also, ostensibly to protect themselves. This can lead to more harm than progress and we as members of the human kind, should be trying to progress for peaceful purposes as a priority, rather than engaging in fights against each other and vying and threatening each other while developing nuclear weapons.
Summarily, due to the several harmful possibilities of nuclear fallouts, our scientific developments in this nuclear arena need to be funneled only into the development of knowledge for knowledge's sake, and not for the purpose of threatening or belittling others by engaging in arms races like nuclear weapon build-up.
 Wikipedia - English. "Atomic Bombings of Hiroshima and Nagasaki". Atomic bombings of Hiroshima and Nagasaki [Wikipedia].
 Quotations Page. "Quote Details: George Bernard Shaw: If history repeats itself,...". Quotations Page - Quotation details [Quotations Page].
 Washington University in St. Louis. "The Atomic Bomb - A Study of Aftermath". Lindsey Anhalt.
 Council on Foreign Relations. "Targets for Terrorists: Post-9/11 Aviation Security". Eben Kaplan.