Nearly what it cost to build them.
It is difficult to provide an exact number as the use of nuclear weapons would have catastrophic global consequences, potentially leading to nuclear winter and widespread devastation. It is imperative to prevent the use of such weapons to protect life on Earth.
Nuclear weapons have the potential to cause massive devastation, including widespread destruction and loss of life. However, it is unlikely that they could completely destroy the world or the planet itself. The use of nuclear weapons would have catastrophic consequences with long-lasting impacts on the environment and civilization.
The main reason that could prevent the US and Russia from using nuclear weapons in a conflict is the principle of mutually assured destruction (MAD). Both countries possess enough nuclear weapons to completely destroy each other, which acts as a powerful deterrent against their use. Additionally, international laws and agreements discourage the use of nuclear weapons due to the catastrophic humanitarian and environmental consequences.
Because it is energy derived from the heat made by a (Hopefully) controlled nuclear reaction. The nuclear reaction involves the nucleus of Uranium 235 (or possibly Plutonium 239) fissioning or splitting which releases a large amount of energy, so it is a nuclear process, not a chemical one such as would occur between atoms or molecules.
U.S. President Ronald Reagan and Soviet President Mikhail Gorbachev came within a hair's breadth of agreeing to phase out their stockpiles of nuclear weapons. General Zhu Chenghu of China's National Defense University, made some remarks that stirred an unusual uproar in the West and in the United States in particular. According to reports in the Western media, Gen. Zhu, in responding to questions in a briefing session on China's foreign and security policy with a delegation of foreign journalists based in Hong Kong, seemed to indicate that in a possible military conflict with the United States over Taiwan, Beijing would be no match for the United States in terms of conventional capability. Zhu thus suggested that China should perhaps be the first to use nuclear weapons to deter a possible U.S. intervention. Today, the United States is the only nuclear power that continues to deploy nuclear weapons outside its own territory. The approximately 480 nuclear bombs in Europe are intended for use in accordance with NATO nuclear strike plans, the report asserts, against targets in Russia or countries in the Middle East such as Iran and Syria. Israel has not confirmed that it has nuclear weapons and officially maintains that it will not be the first country to introduce nuclear weapons into the Middle East. Yet the existence of Israeli nuclear weapons is a "public secret" by now due to the declassification of large numbers of formerly highly classified US government documents which show that the United States by 1975 was convinced that Israel had nuclear weapons But as the questions says, there should no be nuclear weapons.
The threat that nuclear weapons would be used.
No, but it would be nice to see them have nuclear weapons, considering that Pakistan and India are nuclear nations.
A large-scale nuclear exchange followed by a conventional war which itself would involve heavy use of tactical nuclear weapons.
Nuclear weapons are a good thing for the United States because they prevent others from using nuclear weapons on the US. In general, the world would probably be a better place without nuclear weapons if it weren't for the fact that they lead to research in all fields of Nuclear Engineering, like Nuclear Power plants and Nuclear Physics. Since nuclear weapons already exist in the world, for the US to get rid of their nuclear weapons would be unwise. Countries that dislike nuclear weapons or even radical terrorist cells and organizations would now have no reason not to launch a nuclear warhead at the US since no retaliation would occur. The strategy of nuclear weapons preventing others from using them against the US is called the Deterrent Strategy.
It would probably be nuclear pandemonium.
No nuclear energy, no nuclear weapons
It is currently impossible to blow up the Earth using nuclear weapons as the planet is too large and the energy required would be immense. Additionally, detonating a large number of nuclear weapons on Earth could have catastrophic consequences for all life on the planet.
nobody
Any decision by the UK to go to war, or to launch nuclear weapons, would have to be made by Parliament.
Because there was no true defense against nuclear weapons. Once both sides had nuclear weapons, the only way to "protect" themselves from the other side was to have so many more nuclear weapons that even if their enemies used all of their nuclear weapons, there would still be nuclear weapons to shoot back with. That way, nobody would use nuclear weapons, because they could never actually "win" that way. This thought process was referred to as Mutually Assured Destruction, or MAD.
At this point in time (2012) Iran is believed to have no nuclear weapons capability at all. However this could end at any time (at which point Iran would be nuclear weapons capable).
Because nuclear weapons are the most deadly of all weapons and can kill hundreds of thousands of people at once. Also, people will always get suspicious if a country is secretly making nuclear weapons e.g. Iran and USA. IF one country wants to build nuclear weapons then their neigh ours would want to too