Trump deemed that unfair, and last week he slapped a 10 per cent tariff on another $200 billion of Chinese exports to the US, due to go into effect at the end of this week. He warned that if China retaliated again, he would impose a similar tariff on all the rest of China's exports, another $267 billion.
Trump also threatened to raise the rate of the tariff to 25 per cent if there is no US-Chinese deal that meets US requirements by the end of the year.
Did he imagine that this threat would force an autocratic regime like China's to back down and lose face? Who knows?
The Chinese replied hard and fast, announcing a new tariff on all the rest of America's exports to China, worth some $60 billion.
China, trying to lower the temperature, is keeping its tariffs on US goods down to 5 per cent for the moment, but it can't hold that line forever if the US goes on ratcheting up the ones it has imposed.
Trump has got the trade war he was clearly itching for and this trade war will probably not be settled for a long time.
Multi-billionaire Chinese businessman Jack Ma predicts that it could last 20 years. As long as it lasts, it will poison relations between the world's two great powers.
Trump seems to think that China's economy is now so wobbly that the tariffs will push it over the edge, forcing it to come to the US begging for mercy.
It's true the Chinese economy is growing very slowly, if at all; nobody believes the official figure of 6 or 7 per cent annual growth. It's also true that the Chinese financial system is as overloaded with bad debts as American banks were in 2008.
But China is only a sham capitalist economy.
If lost exports to the US trigger a financial collapse in China – an unlikely but imaginable outcome – Beijing would slam the doors closed on international capital flows, bail out the Chinese banks, and flood the domestic economy with cheap credit.
In this scenario, it's international trade that would collapse, which wouldn't be in anybody's interest.
Meanwhile, Chinese leader Xi Jinping's regime would be stoking Chinese nationalism and blaming the US for all the domestic misery. Indeed, Xi and the Communist Party hierarchy are coming to the conclusion that Trump's trade war is designed to "thwart China's rise". There can be no compromise with the United States if that is the case.
That's not just Chinese paranoia. There really are those around Trump (and elsewhere in Washington) who are encouraging his obsession with the American trade deficit with China for exactly that reason.
Yet his obsession is completely misplaced — 85 per cent of the seven million American manufacturing jobs lost since 2000 were eliminated by automation, not by trade.
This nonsense is going to go on for a long time, and everybody will end up at least slightly poorer, but it probably won't bring on the Second Great Recession. It may, however, start the Second Cold War.
Gwynne Dyer's new book is "Growing Pains: The Future of Democracy (and Work)"