Incoming US President Donald Trump's approach to world affairs is likely to be driven by external events rather than any sort of consistent vision. Credit:Getty Images "Ready or not, China has become the de facto world leader seeking to maintain an open global economy and battle climate change. In effect, President Xi has become the general secretary of globalisation." In contrast, Trump has promised to shrink America with his mercantilist policies, his "border tax" and weird veneration of a manufacturing-based economy that doesn't really exist anymore. America's light goes out In economic terms, the eclipsing of American power is well underway. Dominance went a good while ago with China the key driver of global economic growth this century. By the World Bank's reckoning, China's economy is already bigger on a purchasing power parity basis. In absolute terms, the American economy remains substantially larger but the cross-over point appears to be within the next decade, depending on how you want to fiddle your assumptions.

Beyond bragging rights for being "the biggest", that really doesn't matter all that much – first, second, whatever. A world with multiple large, strong, interrelated economies is a good thing. A world of rising economic equality would be a very good thing. More important is the aspiration that the better part of American Exceptionalism offered. Trump is extinguishing the American "light on the hill". While the US has certainly made mistakes during its century, some of them terrible, it has been an overall force for good, offering a liberal, democratic, outward-looking global leadership. Under Trump, we're to have none of that. Trade agreements must favour the US. NATO is out of date. Putin is a mate. Climate change is a Chinese conspiracy. Israel can do whatever it likes. The military, should it become engaged, is to be unleashed from all humanitarian restraints. And that military, already by far the world's largest and most powerful, is to have many billions of dollars more fed into it. Sectarianism is fine. Sexism is fine. Racism is a ticket to the White House. The US is about to have a president who might not himself know if he's lying or not at any given tweet. Just as Britain shrinks through Brexit, America shrinks by having Trump as its president.

And then it becomes dangerous if those who voted for Trump realise they've been conned. As argued here previously, Trump's biggest lie was in convincing so many people that America wasn't great, that it had to be made great again. America is great on any number of counts. It has a large and powerful economy. In energy terms the US consumes the better part of a quarter of the world's energy while making up only about 5 per cent of the world's population. The Scientific American reported the nation was responsible for half the world's solid waste. Its military overshadows all others. It wins the most Olympic medals. In soft power, the US dominates – we watch its movies, we follow its stars, we play its music, we copy its broadcast news, we are enslaved to its social media and technology giants. It's possible that more people outside the US than in it are aware of the main issues in American politics. Certainly the rest of the world is more aware of the US than the US is aware of the rest of the world. That America is not great for many Americans has little to do with Trump's various scapegoats – the Chinese, Mexicans, Muslims, the media. The disenchantment, the stagnation, the increased inequality, the third-world-within-first-world America is a problem of distribution and under-investment in people. It's the failure of the trickle-down economics that Trump is promising to double down on. The America of tax-dodging billionaires has become much wealthier. Cutting income tax, company tax and abolishing death tax will make it wealthier yet. It will do nothing for the angry millions who've been told America isn't great.

Dubious future Trump's ability to con and mislead, primed by years of Republican propaganda, proved so good that he convinced people things were getting worse even when they were turning the corner. Obama's "trickle up" has been working. Millions of jobs have been created in the past two years, median incomes have risen and poverty reduced. The doctrinaire return to trickle-down promises to reverse that once Wall Street's sugar hit passes. Even the promised infrastructure boost – perhaps the one good shot in Trump's scattergun approach - may prove short-lived. It seems it will be more a tax break for privatisation rather than an effective injection of serious investment. And the investment that America needs most, the investment in people and their education, faces a dubious future in the hands of right-wing Republicans. Oh, America will still be great overall and exceptional, "beautiful, so beautiful" for those at the top. But under President Trump, the US will no longer lead. The end of the American Century could be made no starker than by an authoritarian communist president being left to claim leadership as America vacates that role.

The strange little cabal of Trump fans in Australia won't notice and shouldn't be noticed. There is no reason to them, other than an apparent unifying hatred of anything perceived liberal or "left" and a primitive fear of "the other". They are our own little throwbacks to supposedly simpler times of unchallenged white supremacy. And, in time, they may appear as quaint as the English gentlemen near the end of the Imperial Century, puffing cigars and passing the port in London clubs, secure in their knowledge that God was an Englishman. Sic transit gloria mundi.