IRAQ, is not known to have any nuclear weapons
USA
Soviet Union (now Russia)
France
China
Other known nuclear powers India
Pakistan
fifth rank in nuclear weapons
No nuclear weapons have been used since World War 2. There were testings done by Russia and possibly other countries but they were never used against other nations.
Two nuclear weapons ended World War 2.
There were no nuclear weapons in WW1. The nuclear bomb was not invented until WW2.
Russia currently owns the biggest stockpile of nuclear weapons in the world. Also Russia made and detonated the biggest nuclear bomb in history called the Tsar bomb.
fifth rank in nuclear weapons
If the majority of the members of the United Nations or the majority of nations that sit on the UN's Security Council believe that another nation acquiring nuclear weapons is a serious threat to world peace, economic sanctions can be set against such a nation. The UN can also send in inspectors to determine if a nation is becoming a threat to world peace because of it building a nuclear weapons system. If all the members of the UN's Security Council vote to sanction trade or funds of a threatening nation, that sends a powerful message to the offending nation.
If there are just enough nuclear weapons so yes they can destroy the World.
No nuclear weapons have been used since World War 2. There were testings done by Russia and possibly other countries but they were never used against other nations.
Two nuclear weapons ended World War 2.
There were no nuclear weapons in WW1. The nuclear bomb was not invented until WW2.
Russia currently owns the biggest stockpile of nuclear weapons in the world. Also Russia made and detonated the biggest nuclear bomb in history called the Tsar bomb.
One reason is that an unstable nation with nuclear weapons could pose a threat to the rest of the world.
Egypt is not believed or suspected to have nuclear weapons, or a nuclear weapons program, at this time (May 2009). See Related Link for a discussion of the world's nuclear powers.
This depends on your definition of Commonly Nuclear weapons have been used twice in the history of the world. The other view is that they have been used twice to often.
Nuclear weapons only serve as a deterrent to war when both warring nations possess them. If only one nation has them or neither do, a conventional war is still very possible. That is why all of the Cold War wars occurred in third world countries where nuclear weapons were not present. In contrast, the Cuban Missile Crisis (and the corresponding Turkish Missile Issue) did not lead to war between the USA and the USSR specifically because both nations had nuclear weapons which could effectively serve as a deterrent to the other.
In the most basic sense, proliferation of nuclear weapons is the spread of nuclear weapons and weapons usable technology in the world. In a much broader sense, it refers to the acquiring of capability to produce nuclear weapons, or weapons-grade nuclear material (high-enriched uranium, plutonium) by states previously not possessing them.