I fail to see the chain of reasoning here. So we didn't reprocess because we feared proliferation? Then how would our not reprocessing have any effect on the decision of India, et. al. to reprocess for themselves? The Cold War was still in effect at the time of Carter's decision, and since India at the time was aligned with the Soviet bloc, our huffing and puffing about a worldwide ban on reprocessing would probably have spurred any effort by India to reprocess, rather than stopping it.
In any case, proliferation is the weakest of all arguments against reprocessing. Carter could have very reasonably have used the argument that reprocessing was expensive and unnecessary at the time (as it still is) due to the low cost of fresh fuel, and that we would be better off storing the spent fuel for a generation or two until better, cheaper reprocessing tech gets here. Carter's decision to not reprocess was an obvious cave-in to the luddite lobby, which in the absence of any roadmap to reprocessing can claim that "nuclear waste is forever" if we have to store spent fuel until it decays by itself millions of years from now. Hence thosee silly schemes for inventing apocalyptic runes for marking "nuclear waste" so that our distant descendants will remember what it is. What they are not telling us, of course, is that all those years of decaying radioactivity represent the waste of innumerable gigawatts of energy that we could be using in our own century, given eventual reprocessing.
Now that the possibility of anthropogenic warming has become an issue, Carter's decision looks even worse than it did then. Even the left admits that if their worst fears about carbon are verified, humanity may prefer going nuclear to going caveman.
