I'm no economist, but this doesn't pass my logic test. You're saying that the world's wealth is fixed and we can only change the way that it's distributed. I would think that's a highly controversial statement, even to the most strident opponents of a fiat currency.
Thinking about it from first principles, wealth is the excess of production over what we need to fulfil our basic needs. So in subsistence economies, all effort must be expended to feed and shelter people (and yes, of course in many countries there's not even enough to do that), and there is no "wealth". In first-world countries, because of the efficiencies obtained by technology and mass production (enabled by the trust that comes from stable governments etc), we can spend much of our time creating wealth with the labour that is freed from food production. Some is used, for example, to build nice houses, or make cars, etc. When you can feed yourselves, give everybody a house and car, and still have labour left over, then you start entering industries like tourism and entertainment, and so on. A society applies its labour first to the items on the bottom of Maslow's hierarchy of needs, and as it becomes more efficient, the spare labour is applied to higher and higher order needs. Wealth is measured by how far up the hierarchy you can afford to spend your money.
When third-world countries improve the efficiency of their farming, for example, new wealth is created. There is no overall loss from that; some competitors may feel the pinch from competition etc, but the whole world is producing more than it was before and is thus wealthier. Much of the labour that was used for farming can now be used to build houses.
Putting it from the opposite perspective, if dollars are fixed, would you argue that the overall financial gains from, say, the Boxing Day tsunami outweigh the losses? Surely the destruction of so much property and labour (sorry to sound callous; this was an enormous human tragedy but I'm talking specifically from a financial perspective here) can only have decreased the world's wealth?
When somebody allows a task to be done using less labour, they add to the world's wealth. That labour can then be used to address higher-order needs. Overall, the world is wealthier.
