though research into the possibility of strategic defense would not violate any provision of SALT I, deployment of such a system, at least on the scale being discussed here, would do so. But it is not clear that it is for that reason bad. Arms control treaties are, after all, not ends in themselves; they are means to preserving national security and international peace, as they themselves make clear. 14 They should remain in force only so long as they help to achieve the end for which they were established. But SALT I makes sense only in the context of a strategy of mutually assured destruction, of vulnerable populations and invulnerable retaliatory forces. And that, as we have seen, is a policy which Bishops, Pope and President all agree is acceptable only as an interim strategy!
Second, critics object that implementation of strategic defense would open a dangerous window of instability, a period in which the Soviet Union would see itself as having one last shot at the American nuclear arsenal before it became forever out of reach, protected by the strategic defensive shield. This is, of course, a danger. Careful coordination with our adversaries would be necessary to assure that we, and they, deploy strategic defensive systems in such a way that no such window of instability is opened. And the Reagan administration is explicit about the fact that the Strategic Defense Initiative should be "a cooperative effort with the Soviet Union, hopefully leading to an agreed transition toward effective non-nuclear defenses." 15 But the problem, though real, does not seem insuperable.
The real question seems to be, not whether strategic defense would be morally superior to deterrence by threat of nuclear retaliation, but whether it would work, and whether we can afford it. Both questions, however, seem premature. Strategic defense is not, at present, a possibility. President Reagan's Strategic Defense Initiative proposes only that we initiate "a long-range research and development program," to see just what the possibilities are. The research will itself, of course, not be free, but as President Reagan asks, "is it not worth every investment necessary to free the world from the threat of nuclear war?" To which we might add, given what we have said about the moral superiority of this strategy over the alternatives, would it be morally permissible to ignore what may be the only road to the elimination of nuclear weapons?