Don Davis article

I read this article. It made the point that we are in a race to
learn enough about the various components of life on earth to enable
a successful rendition of earth (successful defined as capable of
sustaining our species without earth)before we destroy it. In making
that point, Davis said that we had squandered the money we could
have used to make a lunar settlement to delay the takeover of S.
Vietnam by the communists by only ten years. What I am wondering
is, where does he get the idea that ten years is "only." Ten years
might have made the difference between enabling a world communist
movement and the actual outcome of the twentieth century, the end of
communism as a viable movement. We might have bought the end of
communism with that ten years' delay. I am not arguing that is the
case, since I haven't done any homework on it. But I think it's
sloppy science on Davis' part to assume that ten years is "only" ten
years rather than a significant ten years, just enough time to
defeat communism. Maybe the moon was not too expensive a price to
pay for that end.