If Xi Jinping, China’s supreme leader, understands anything, it is the nature of power. That is why his first call during a week-long state visit to America was not on the political leaders in Washington but on the business elites in Seattle.

Mr Xi has concentrated more power in his bearlike, avuncular personage than any Chinese leader since Deng Xiaoping, and arguably than Mao Zedong himself. The irony is that he heads a nation that looks more vulnerable, in some ways, than it has done for years. China’s economic model is audibly creaking and in need of urgent repair. Growth has slowed to practically half its level of a few years ago [CAN YOU SEND YOUR SOURCE FOR THIS?]. This week, figures revealed that the manufacturing sector, once the economy’s mainstay, is slowing fast.

The US is exactly the reverse. Compared with Mr Xi, who has few checks on his power and who can expect seven more years in charge, Barack Obama looks like a spent force, despite his recent active streak. He must answer to a hostile Congress and has barely more than a year left in office. Yet America is resurgent. Its tech companies are on top of the world; it has unearthed vast, cheap energy resources at home; and its economy is surging back from the self-inflicted financial crisis of 2008.