I F YOU WANT to understand the commercial relationship between America and China, it is worth tracking the paths of two powerful people who have dedicated their careers to it: Henry Paulson, a tough-as-nails former head of Goldman Sachs and former American treasury secretary, and Wang Qishan, a well-read banker and bureaucrat who is China’s vice-president. Since the 1990s they have worked together, episodically, on reforming state-owned enterprises ( SOE s), boosting trade and fighting the 2007-08 financial crisis. Now they are trying to bridge a deep divide.

The two appeared on November 6th and 7th in Singapore at the New Economy Forum—a gathering of business royalty organised by Michael Bloomberg, New York City’s former mayor, designed to air trade tensions and look for a response to populism. With Henry Kissinger sitting in the front row, Mr Wang warned that the “polarisation of right-leaning populism” in the West was stoking anger and destabilising the global order. A day later Mr Paulson stood up and complained about China’s misconduct and warned of a new “economic Iron Curtain” falling between China and America.

Messrs Wang and Paulson first worked together in 1996. Mr Wang was a high-flying reformer in charge of the giant China Construction Bank and was orchestrating the flotation of China Telecom, the first huge SOE to list in New York. Goldman was the underwriter. By 1997 he was an official in Guangdong province and asked Mr Paulson to help restructure Guangdong Enterprises, a crippled SOE . The two men ascended in parallel. In 2001 when China joined the World Trade Organisation, Mr Paulson was running Goldman; Mr Wang guided China’s economic-reform agency.

By the time Mr Paulson became treasury secretary in 2006 he had visited China 70 times. He led a new “strategic economic dialogue”—an almost continual bilateral discussion that covered everything from currency movements to pirated DVD s. Mr Wang became vice-president three days after Bear Stearns was rescued in March 2008. When Lehman Brothers failed in September, the mesh of friendships and institutional links between the countries’ leaders helped contain the crisis. China refused to dump Treasury bonds and stimulated its economy to offset America’s slump.

In this golden era of superpower relations other executives formed strong relationships with China, too. Stephen Schwarzman, the head of Blackstone, a private-equity firm, sold 9% of it to a Chinese state fund in 2007 (it sold out in March of this year). Multinationals such as General Electric had close contact with China’s leaders. One boss recalls his board huddling round Jiang Zemin, China’s party chief between 1989 and 2002, for a group photograph.

A commercial edifice was then built on these relationships, although not the one that might have been expected. China has not opened up its financial industry—Goldman makes less money from Asia now than in Mr Paulson’s last year in charge and has only 1% of its balance-sheet exposed to China. Still, in total USA Inc made $450bn-500bn of sales from China last year. An elite of a dozen or so firms, including Apple and Boeing, make over $1bn a year in profits. China exported $500bn of goods to America. Measured this way the relationship is roughly in balance.

In private many American executives still view China as the world’s most important market after their own. In public they have turned hawkish. This may reflect an intimidating political climate at home. On November 9th Peter Navarro, a White House trade adviser, said that Wall Street bankers were acting as China’s “unpaid foreign agents”. But there is real disillusion among executives, too. They persuaded themselves that Chinese SOE s might metamorphose into private-sector firms, and the country would become a market economy with property rights and a level playing-field for foreign companies. It has disappointed on both counts. Mr Paulson says that American business has gone from “advocate, to sceptic and even opponent” of past American policies towards China.

A decade ago, whenever tensions arose they were defused with flurries of phone calls and red-eye flights. But the habit of frequent, intimate discussions has atrophied and trust has faded. In Singapore Mr Wang insisted that China is open for talks on trade, which may resume ahead of the G 20 meetings on November 30th and December 1st. He is known as the Chinese leader with a deft touch with foreigners—unlike most of them, he talks off the cuff and makes jokes. Yet this time his punchlines did not raise a laugh. One American involved in the face-to-face negotiations says that for a year China has refused to budge on intellectual-property theft and state intervention. Mr Wang’s visit was a “waste of jet fuel”.

Just as business responded to China’s opening up in the 1990s, so it is adjusting to a new, de facto cold war. Charles Li, the head of Hong Kong’s exchanges, says the two economies are like saltwater and freshwater systems that meet but do not mix well. America’s tariffs on Chinese goods are due to rise from 10% to 25% on January 1st. Multinationals are stockpiling inventories inside America. Logistics companies have plans to reconfigure aircraft fleets. Speculation swirls around the firms with the most global supply chains. On November 5th Apple revealed that it has bought 2,450 acres of land in America in the past year, prompting chatter that it might bring more production home.

A long march, not a sprint

If, in 1996, Mr Paulson and Mr Wang could have seen the world today, they would have been awed by the scale of the commercial links between China and America, but worried by their fragility. Their personal instincts now sit uneasily with domestic politics. Mr Paulson is a Sinophile in a more nationalist America; Mr Wang is an economic reformer at the heart of an autocracy. But as they survey the dismantling of their 20-year project, these two masters of the long game might console themselves that the political tides can shift again, and that, in time, the attempt to find an accommodation between America and China may resume.