Isn't the point we've been - and we've learned there really isn't much there and it's not worth the effort?

Even at the time people suspected that - but at least there was a chance of finding something unexpected.

As to the knowledge is has been done, and therefore could be done again - sure that's valuable, but that knowledge belongs to the whole world not just to America.

And in terms of national prestige or uniting goal - wouldn't it be better to have a goal to create a long term sustainable energy economy for example. I think that has more strategic value than putting a man back ( or women for the first time ) on the moon.