PROGRESS OF NUCLEAR DISARMAMENT Wu Zhan（26） During the last decade, the U.S.-Soviet/Russian nuclear arms control has undergone changes from limiting the quantity of nuclear weapons and preserving the status quo to real and substantial reduction of those weapons, from limitations on an equal footing to unequal cutting, and from difficult negotiations amidst mutual suspicion to successful agreements. All these changes have come about on account of the softening of position on the part of the Soviet Union and Russia at present caused by economic failure.