Today, for the first time in almost 50 years, the United States stands on the verge of attaining nuclear primacy. It will probably soon be possible for the United States to destroy the long-range nuclear arsenals of Russia or China with a first strike. This dramatic shift in the nuclear balance of power stems from a series of improvements in the United States' nuclear systems, the precipitous decline of Russia's arsenal, and the glacial pace of modernization of China's nuclear forces. Unless Washington's policies change or Moscow and Beijing take steps to increase the size and readiness of their forces, Russia and China -- and the rest of the world -- will live in the shadow of U.S. nuclear primacy for many years to come.

(...) (...)

the sort of missile defenses that the United States might plausibly deploy would be valuable primarily in an offensive context, not a defensive one -- as an adjunct to a U.S. first-strike capability, not as a standalone shield. If the United States launched a nuclear attack against Russia (or China), the targeted country would be left with a tiny surviving arsenal -- if any at all. At that point, even a relatively modest or inefficient missile-defense system might well be enough to protect against any retaliatory strikes, because the devastated enemy would have so few warheads and decoys left.


Source (American): Lieber, Keir A.; Press, Daryl G. The Rise of U.S. Nuclear Primacy. Foreign Affairs, March/April 2006, Vol. 85 Issue 2

Keir A. Lieber, the author of War and the Engineers: The Primacy of Politics Over Technology, is Assistant Professor of Political Science at the University of Notre Dame
Daryl G. Press, the author of Calculating Credibility: How Leaders Assess Military Threats, is Associate Professor of Political Science at the University of Pennsylvania