The idea of strategic stability and the policy of MAD had some merit during the Cold War, when the United States, our allies, the Soviet Union, and China were still the only nations with nuclear and ballistic missile capacities. That idea and policy can no longer be relied upon, as events since the Cold War have clearly shown.
Although the rules of warfare were indeed revolutionized by the nuclear age, technology can equally be used to intercept missiles for defensive purposes—-in the words of Ronald Reagan, to save lives rather than avenge them. It is true that ballistic missiles revolutionized the rules of warfare by introducing an new and advanced form of offensive technology: an ICBM armed with multiple nuclear warheads could leave an underground silo in Russia and deliver its payload to cities within the United States in just over a half an hour.
What may have been less clear during the Cold War has become more clear with changed circumstances. There is no such thing as “absolute weapon” which is so unthinkable that it cannot be used.
The world has many actors who conceivably do things civilized nations may term unthinkable, such as the destruction associated with weapons of mass destruction. The existence of these means one cannot rely upon the existence of rational actors. North Korea, Iran, and Pakistan are unlikely to have a concern for their population. These and other countries may instead decide to launch an attack which cannot immediately be traced back to its country of origin, perhaps by giving terrorists a missile to be launched from a ship off one of America’s coasts.
Strategic clarity requires that we not be constrained by thinking developed in another time for another set of circumstances. The time has come to move beyond the MAD framework, and to reinforce deterrence with defensive as well as offensive measures.