This report addresses the dangers of reliance on the assured-destruction criterion in strategic nuclear planning. It argues that, contrary to popular belief, the example of superpower arms restraint in SALT negotiations will not necessarily encourage arms restraint by others. SALT outcomes that preclude strategic modernization would encourage nuclear proliferation by making nth-country retaliatory programs more effective and less costly. To limit nth-countries' threat capability, qualitative improvements in U.S. capabilities for controlled nuclear response are desirable. Political decisionmakers must be persuaded to assign such modifications high priority, and to argue effectively for them in Congress and elsewhere. Minimum U.S. flexibility requirements include (1) global surveillance and communication under all conditions; (2) preplanned limited retaliatory options for adverse contingencies and crises; (3) speedy implementation of a chosen option to destroy targets without collateral damage; and (4) continent-wide aerospace defenses providing good attrition against small attacks. These would buttress superpower nuclear guarantees to allies and NPT signatories.