Rage against the Imperialist Machine?

There's been quite a bit of anger of late about the injustice of imperialism, such as Laura's and Leigh's posts. I by and large tend to agree with it, but it raises an interesting point. What would Europe and the West have been like without imperialism? Would the West still enjoy the standard of living and wealth it now has if not for imperialism? Would we even be in a position to complain about imperialism if it were not for imperialism? Scarcity means, unfortunately, that the world's resources aren't infinite. To some extent, one nation's loss comes at another's gain. So without imperialism, we might have a more equitable distribution of resources around the world, but that would mean decreased standards of living elsewhere.

I'm willing to accept this as a consequence of a non-aggressive, voluntary global village/community/[insert warm fuzzy platitude here]. But I think we should keep in mind that you can't have your cake and eat it too.