SDI was criticized for potentially disrupting the strategic doctrine of Mutual Assured Destruction. MAD postulated that intentional nuclear attack was inhibited by the certain ensuing mutual self-destruction. Even if a nuclear first strike destroyed many of the opponent's weapons, sufficient nuclear missiles would survive to render a devastating counter-strike at the attacker. The criticism was that SDI could have potentially allowed an attacker to survive the lighter counter-strike... encouraging a first strike by the side having SDI. Another destabilizing scenario was countries being tempted to strike first before SDI was deployed, thereby avoiding a disadvantaged nuclear posture.