We have been hearing warnings about "the decline of the West" for almost a century now, since Oswald Spengler made that phrase the title of his hyperbolic 1918 bestseller. But for the first time, it appears likely that these warnings will become true: By the end of my life, it's almost certain that Europe and North America will no longer be the world's largest economic, cultural and military forces.

By 2050, according to a plausible projection by the Asian Development Bank, Asia will have a 51-per-cent share of the global economy, next to 18 per cent for Europe and 15 per cent for North America. This is often discussed as a defeat: If the others become stronger and more successful, doesn't that mean we'll become weaker and less prosperous?

But that ignores what's really happening. In recent years, the West has declined relative to Asia. But it has not declined in absolute terms: Western economies have grown by an average of 1 per cent per year in recent decades; quality of life and income measures have stayed relatively stable or increased slightly. What's occurring is not a decline, but a global rebalancing: "They" are becoming more like "us," but we're no less like ourselves than before.

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Is it possible that this could be the best thing that ever happened to our quality of life? That's a question posed with great rigour by economist Charles Kenny of Washington's Center for Global Development. Being born in North America or Europe today is "like winning the birth lottery for the human species," he writes in his book The Upside of Down: Why the Rise of the Rest is Good for the West – never has there been a better time or place to be born. Not only that, but, according to projections, "the only thing better than being born today in America or Europe will be the chance to be born tomorrow in those very same places." He concludes that "the rise of 'the Rest' is one big reason why that is true."

In terms of our financial, economic and employment stability, the rise of the global East and South (and our decline in comparison) is hugely beneficial to the West. Economist Homi Kharas predicts that the size of the global "middle class" – those earning $4,000 to $36,000 a year – will rise from 1.8 billion people now to 4.9 billion in 2030. Two-thirds of them will live in Asia, and only a fifth in the West.

This will mean greater consumer choice and a lower cost of living. But it also means huge new markets for Western businesses. Starting this year, for the first time China will be importing more goods than the United States does. More than half of the world's exports are currently imported by the developing world.

As we already know, this is not a one-way loss of jobs to a wealthier East: The rise of Asia and South America have brought major investments into Western countries and helped create the return to near-full employment in places such as Germany and Canada. Not all is well in Western economies, but if anything, the rise of Asia has helped rather than hindered recovery.

Beyond money, goods and services, there are more important reasons why the West will benefit from this rebalancing. The list of the world's top 500 universities now includes 23 Chinese schools, up from nine in 2003. This is sure to rise sharply, with major universities in the Indian subcontinent, South America and Africa joining the list.

That will give our children a far greater global choice of educational futures. But more important, Mr. Kenny notes, is "improvements in health and education and changing norms and values that suggest we're entering a healthier, more peaceful and more cosmopolitan time for the planet."

Religious intolerance has fallen in 90 per cent of countries, according to the World Values Study, going from 44 per cent to 33 per cent of the world's people in the past decade. Tolerance of homosexuals has risen similarly, homicide and war are both at their lowest levels in recorded history and population growth rates are plummeting worldwide – all the result of education, urbanization and prosperity. This also the best plausible defence against climate change; studies have shown that its victims will overwhelmingly be those in absolute poverty, whose worldwide numbers have fallen in half in the past 20 years and could plausibly hit zero; the rebalancing will create a more climate-resistant world population. And countries with thriving economies will be able to afford climate remedies.

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What about military decline? This could be crucial: Prosperous countries less prone to violence are less likely to require military intervention, so we'll be shifting to aid and diplomacy. (It's already happening.)

What we in the West will lose is the ability to boast about Western supremacy. We'll face the same challenges as now, and there will be headlines about defeat, but beneath it all, our lives are likely to be even better.

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