The program known as the Strategic Defense Initiative (SDI) includes research on a variety of technologies--many aimed at distinct phases of the ballistic missile flight path. For each phase--boost, post-boost, mid-course and terminal --a defense would require successful surveillance, target acquisition, tracking, guidance of the weapons, and kill mechanisms. Are the objectives of SDI technically feasible? The answer will depend primarily on what specific objectives strategic defenses ultimately seek to achieve--protection of population, of missile silos, of other military targets. Within that context, the answer will further depend on the capabilities of the technologies and on the potential countermeasures and counter-countermeasures of each side.
Negotiations between the United States and the Soviet Union on nuclear arms control are at an impasse. Following the deployment in Europe of the first U.S. Pershing II and cruise missiles in the fall of 1983, the Soviet Union walked out of the negotiations on intermediate-range forces (INF) and refused to agree to a resumption date for the negotiations on strategic nuclear forces (START). Whether and under what conditions the negotiations will resume is uncertain.
In military and technical terms, we can envisage agreements to limit strategic arms which would be sufficiently verifiable to be enforceable and which would enhance both the security of the United States and the security of the Soviet Union. On-site inspection is no longer the immovable roadblock that it has been in the past. Unilateral means of verification, available to both sides, provide forms of inspection as effective for some purposes as on-the-ground surveys.
Uncertainty is necessarily the lot of the planner, since the deals with the future. Uncertainty can never be completely removed. However, it can be compensated for, and to do so is a continuing responsibility of those who plan military forces. Primarily this can be done by insuring, in so far as we can, that future weapons and forces will be adaptable to the right range of defense needs or, as defense planners often put it, by insuring flexibility.
