SEOUL -- The global balance of nuclear deterrence is changing. With China rapidly expanding its stockpile of nuclear weapons, the U.S. and Russia are losing their dominance in this category of arms. As nuclear weapons proliferate to countries such as India, Pakistan and North Korea, it has become more difficult to advance nuclear disarmament and make deterrence work.
The Federation of American Scientists estimates there were some 12,000 nuclear warheads in the world as of last year. In addition to the five nuclear weapons states recognized under the Treaty on the Non-Proliferation of Nuclear Weapons -- the U.S., Britain, France, Russia and China -- India, Pakistan, Israel and North Korea are known to have nuclear arms.