I worked on the problem of anti-ballistic missiles and strategy in the summer of ’62 and again in the summer of ’63, in company with a lot of very interesting people. And we wrote a report in ’63 summarizing our conclusions, but the trouble was that we included in the report estimates of numbers of nuclear weapons—which was a very, very highly classified piece of information until quite recently. As a result the classification level of the report was very high and very few people read it. I didn't realize that that was a big problem. I assumed the important people in government had plenty of clearances and that it wouldn't matter. But somehow it did matter and the report was not so very influential. But the point of view ultimately prevailed. After many, many, many years there finally was a treaty, SALT 1, that required both the US and the Soviet Union to exercise very great restraint in deploying these systems. Each side could have one and the United States chose to have it...to have the anti-ballistic missile system protecting a missile base, which is stabilizing, instead of having it protecting a big metropolitan area, which would be destabilizing. So, things came out all right in that... in that department, but it took a long, long time.