It's never a pleasant conclusion to draw, but to not do so would be to ignore reality. In a world where governments shovel tens of billions of dollars into the furnaces of war like so much coal and yet manage to lose the equivalent of nearly half of NASA's 2010 budget, where the Governator has declared an imminent threat of "fiscal meltdown" in California and historians like Niall Ferguson opine about the United States' fall being hard, fast, and soon, certain things will fall by the wayside. Space is one of them - space has always been one of them; recall that it was the leaders who ruled in prosperous times that established the tradition of pillaging NASA for beer money year after year.
If we couldn't take substantial steps into space when our lands were flush, if the barriers to entry have been flung up so high that the free-spending twentieth century couldn't climb them, what does that say about our hopes for the twenty-first?
At least space investment and military investment will be one and the same in the twenty-fourth century. Don't listen when they claim that Starfleet isn't a military organization. It totally is.
Recently it seems like the entire concept of space colonization has come under attack - the Mundane SF blog, which has been thankfully dead for a couple of years now, seemed to take the viewpoint that science fiction which portrayed space settlement was escapist tripe that could only detract from the mission to save Earth, that pretensions that life was possible elsewhere were practically crimes against the future. That blog really did a lot to sour me on the mundane sf movement. But moving on...
As the twenty-first century unfolds, I think we're faced with a situation that's without significant precedent in our recent history. There's no more frontier. The world has been ranged over, tamed, and developed. The blank spots on the map have been filled in and there's nothing left that's unknown. Granted, there's plenty of room for personal exploration, as my walk-until-I-cannot-walk-anymore experiences in Vancouver attest, but societies are better off with the capacity for pressure release than they are without. Take the example of the Pilgrims who settled Massachusetts, or the Huguenots that were kicked out of France. It's groups of like-minded people, not teeming masses yearning to breathe free, that space colonization would benefit.
If only we could afford it. I know that there are plans underway to open up the space business to private enterprise, that one day in the not-too-distant future NASA might finally be able to come the research agency it was meant to be and not just a space truck dispatcher. In the end, the money's got to come from somewhere - and in a climate like this, I can't help but think that the money may end up staying close to home. After all, time travel is perfectly possible in theory - you just have to fly one mouth of a wormhole around at relativistic speed - what if space colonization is the same way?
It'd be an awfully depressing notion to consider, that a perfect blue sky is an almost-perfect prison.