Robert,
The UN treaty status site claims that the Outer Space Treaty was ratified and signed by the US. I guess I was confusing internal UN shenanigans with US internal ratification. It also claims that the US’ status with respect to the Moon Treaty is ‘Non-Party’ without signature, whatever that means. Both treaties disallow sovereignty claims on the Moon and direct all efforts in space to be ‘co-operative .. peace …’ (the language looks identical for some of the articles) so it isn’t even cold comfort for me.
I do agree that private development of space can still occur (as space stations would clearly be sovereign/private entities) but I think putting the Moon off-limits is a major deterrence. The Moon is a prize worth trillions of dollars and could be the greatest force to draw private enterprise into space. As it is now, that prize is just taken off the table. Why would anyone even start making long-term plans to do something so expensive when it will not be legally well-defined? It makes them concentrate on shorter term projects in orbit, I would guess, which are much less lucrative. Throw the Moon in and, all of a sudden, a 40-year program looks like a solid private investment.
I like your analogy to nuclear subs, but I would just note that they were developed within an atmosphere of the most competitive nature imaginable. Life and death. There is nothing comparable in space, as it stands now and the treaties are all about kumbaya sessions.
I also worry much less about the enviro-whackos, these days. They will be cut to shreds by oil prices and their refusal to exhibit any sense, or love for Mankind, in that debate.
We always keep escape clauses in our international treaties (that I’ve seen) but we almost never pull out of them (Bush got raked over the coals for legally trashing the idiotic ICC, with people calling him a treaty-breaker even though it was all according to the treaty). I mean, we just went through that strange set of actions concerning the Arctic and Russia’s attempt to make sovereignty claims there. It would be nice if Bush would signal our intent to pull out of any sovereignty-restricting treaties for outer space and explain how we developed the West and how that model is going to serve our development of space. It sounds nice to me 
