First Strike - Destabilizing Role of Missile Defence

Destabilizing Role of Missile Defence

Any defence system against nuclear missiles such as SDI will be more effective against limited numbers of missiles launched. At very small numbers of targets, each defensive asset will be able to take multiple shots at each warhead, and a high kill ratio could be achieved easily. As the number of targets increases, the defensive network becomes "saturated" as each asset must target and destroy more and more warheads in the same window of time. Eventually the system will reach a maximum number of targets destroyed and after this point all additional warheads will penetrate the defences. This leads to several destabilizing effects.

First, a state that is not building similar defences may be encouraged to attack before the system is in place, essentially starting the war while there is no clear advantage instead of waiting until they will be at a distinct disadvantage after the defences are completed. Second, one of the easiest ways to counter any proposed defences is to simply build more warheads and missiles, reaching that saturation point sooner and hitting targets through a stragtegy of attrition. Third, and most importantly, since defences are more effective against small numbers of warheads, a nation with a defence system is actually encouraged to engage in a counterforce first strike. The smaller retalliatory strike is then more easily destroyed by the defence system than a full attack would be. This undermines the doctrine of MAD by discrediting a nation's ability to punish any aggressor with a lethal retalliatory second strike.