Conducted upon request of the Congress soon after the arrival of the new Administration, the second Nuclear Posture Review, whose results were made public in January 2002, is marked by a series of important doctrinal evolutions. Its approach is now capabilities-based, and is designed to address a wide spectrum of contingencies, which may originate from hostile states or non-state entities capable of large scale aggressions, in an unpredictable environment dominated by the proliferation of mass destruction weapons and of their means of delivery. The NPR emphasizes a reduction of the central importance of nuclear weapons, whose deterrent role will be shared with high precision conventional weapons systems. At the same time, it also confirms the everlastingness of nuclear weapons in the American doctrine. The Review otherwise indicates that nuclear strategic arsenals will be strongly reduced by the end of 2012, as later agreed in the SORT signed in Moscow in May, although these reductions will be potentially reversible in order to preserve the capability to adapt to any new emerging threats. The NPR also addresses research programs on non-nuclear or nuclear strategic offensive weapons, nuclear weapons test ban issues and the doctrine of use of nuclear weapons. While the first of these three pillars indicates some substantial evolutions, the other two do not bring any considerable change with respect to the end of the nineties. –Summary AFRI-2003