all countries have to denuclearise

I'm not sure exactly what we are debating. 'Having' to get rid of nuclear weapons implies no choice, and I know of no way to force a lack of choice other than through force of arms.What countries should and should not do implies a philosophical choice, which can certainly be argued. Even proving a philosophical ethical (or by inclusion and average moral) choice is not enough, however. This creates a foundation for a valid opinion on ethical grounds, but ignores issues relating to force of arms, especially naval, and the right of cultures to self-determination.Nuclear wepons aren't like conventional wepons, they are area denial wepons. The popular term in the form of the acronymn WMD is more political than strategic. The function of nuclear weapons in war is generally more about strategy than tactical implementation.From a tactical perspective a person looks at the number of nuclear weapons in the world and panicks, generallly with a 'slippery-slope' argument such as 'if someone starts shooting everyone will start shooting and the entire planet will be destroyed'. This ignores strategic military planning for invasion. The military is very fond of redundancy. By having a lot of nuclear weapons in a great many places they are guarding against the tactic used so successfully in world war two of the german blitzkreig. If we reduced nuclear weapons down to merely the essential number necessary to guard tactically, a strategic lightening invasion of the missile storage and launch sites could be accomplised by a concentrated strike at these locations. It isn't very hard in war to achieve local numerical superiority, it's just strategically problematic (logistics and support). Missiles can't launch at the push of a button, no matter what you see in hollywood. They are like rockets, requiring fueling and precise planning before launch.Thus the number of weapons on hand is a military strategic precaution and not an indication of a lack of understanding about the dangers inherent in nuclear war.In truth, the nonproliferation treaty derived from a discussion between the two most common and populous socio-political governmental foundations: communistic and democratic. The most powerful nations derived, at least nominally, from these foundational social memes. Each side had reasons to want to 'arm up' their allies, but there was a very good counter argument to this political motivation: that of stability. Many of the smaller countries weren't socially dedicated to either philosophy. Some were religious, some were effectively dictatorships or monarchies even though they nominally allied with one or the other party. The problem with these types of government is that they aren't considered viable over any kind of long-term social evolutionary span. Monarchies and dictatorships quickly fall, in terms of government systems, especially as the baseline educaiton of the population increases. The demands of technology for governments to adapt and encourage education among their population made these countries worrysome to all of the countries that eventually signed the treaty.Essentially the worry boils down to the fact that most of the governments that had nuclear weapons already were politically stable, having popular support based in social philosophy that would make military or grass-roots overthrow unlikely or, at worst, slow. Other small countries had militaries that were unpopular, outnumbered, unsophisticated in social control techniques, and thus likely to fall into the hands of emotionally charged and poorly educated social groups. These groups were far less predictable and it was feared that they could actually start an all-out nuclear war if they had access to nuclear weapons following a coup.This brings us to Iran and, just as frightening, North Korea. The average level of education in both countries is abysmal. The governments maintain power through force of arms and deception (religion in Iran, propaganda and information in NK) but could be toppled by a concerted effort that threw support behind a rival faction. This would destabalize the country, but would be excessively dangerous if either country had nuclear capability. If any group managed to gain power with popular support they could quickly find themselves having to choose between a complete political collapse or concession to popular demands for the use of nuclear weapons.Nobody wants the use of nukes to be a popular choice by a population, especially a poorly educated, passionate and angry mob.Regardless of how we feel ethically or morally about nuclear weapons, they do exist. No matter how we feel about them ethically or morally, they have uses for naval combat and area-denial that do not include all-out nuclear war or the deaths of millions of innocents, and thus any argument aganst them relies on a logical fallacy of 'slippery slope' when the use isn't full-scale war.I can agree with my opponent ethically and morally, but the reality of the argument explains the political position and does not yeild a viable way to change the political calculous.