I was interested in what people thought about the implications of improving the lives of those in the developed countries vs. allocating those resources to help the less-developed ones.
It depends on what you mean by "help". If by "help" you mean "give them more food", then I don't think that's a good solution. I'll let Daniel Quinn say it:
For ten thousand years we've been increasing food production to feed an increasing population—and for ten thousand years our population has grown. Every single "win" in food production has been answered by a "win" in population growth. Every single one. But, according to our cultural mythology, this doesn't have to happen—and one of these years, magically, it will not happen. The magic will presumably be that all nations will achieve improved social and economic conditions and adopt effective, voluntary family planning, just like the Union of Concerned Scientists recommends. This magic didn't happen last year or the year before that or the year before that or the year before that or the year before that—but one of these years, by God, every guy on earth will put on a condom and super-glue it in place and it WILL work. One way or another, there will come a year when we increase food production—and miraculously there won't be an answering increase in population to consume it.
Our cultural mythology explains why it was vitally important for us to increase food production last year. We HAD to, in order to feed the starving millions. Everyone knows that. But, oddly enough, we increased food production to feed the starving millions, and guess what? The starving millions went on starving. The population went up—but the starving millions didn't get fed. And of course we know why it's vitally important to increase food production THIS year. We've got to do that in order to feed the starving millions. We WILL increase food production this year—there's no doubt of that—but is there anyone in this room who believes that the starving millions will be fed, this year, for the first time in living memory? I guarantee you, my friends, that by year's end this year, the starving millions will still be starving—and I guarantee that our population will have grown by two percent.[...]
Let me explain why those starving millions are not getting fed. Every year here on this parking lot we call earth, the human population grows by about two percent—all segments of it grow by two percent. This means that there are more blue-eyed people here this year than last year—and more brown-eyed people. It means there are more red-haired people here this year than last year—and more brown-haired people. It means there are more people here growing up well fed—and more people here growing up hungry. The starving population goes up just like all other populations, and producing more food can do NOTHING BUT produce more starving millions. We're not making hunger go away by increasing food production, we're just creating more and more people to go hungry. Increasing food production actually INCREASES the number of hungry people, the same way it increases the number of rich people, poor people, tall people, short people, smart people, and dumb people.
It's unintuitive, perhaps, but if your vision of sustainability is that everyone gets fed well then you end up with an unsustainable growth in population. Because you're not just feeding people, you're feeding a culture and a system. And that culture, that system, is what is responsible for the fact that some people are well fed and other struggle to make ends meet. True sustainability must first come from a different culture which has sustainability as one of its inescapable foundations. Hunter-Gatherers who ate the original paleolithic diet had that (not in every case, but for the most part). But even we who eat a modern Paleo diet and support pastured cattle, etc... we don't. Sorry for the length of the quote.