Celebrating 70 years of Communist Party rule, Chinese leader Xi Jinping stood in the open sunroof of a Red Flag limousine and shouted, “Greetings, comrades,” to the masses below. Xi wore a Mao-style suit to his giant military parade, which featured a missile that could carry 10 nuclear warheads and strike anywhere in the United States.

President Trump congratulated him.

There’s been no such support for the thousands of pro-democracy demonstrators in Hong Kong. They’ve been braving tear gas, water cannons and live fire to protest China’s aggressive efforts to take away their semi-independence. Someone spray-painted “The heavens will destroy the Communist Party” on a wall. Amid the chaos, a lone saxophonist played The Star-Spangled Banner.

Toadying to a communist dictator crushing free-market demonstrators is what happens when a president who fancies himself a great negotiator drags his country into a foolish trade war — a conflict bankrupting American farmers and hurting other businesses. China’s economy has suffered as well, but politically, Trump drew the short straw. Xi had his constitution fixed to make him president for life (like Chairman Mao). Trump is up for reelection next year.

So Trump is frantic for a trade deal, and the Chinese know it.

“The worst thing you can possibly do in a deal is seem desperate to make it. That makes the other guy smell blood, and then you’re dead.” Those words come from a 1987 book, The Art of the Deal, written by a real estate developer named Donald J. Trump.

The advice is sound. Trump in August flaccidly downplayed the Hong Kong protests as a “very tough situation” but one for China to handle. Then he was threatening to ban Chinese companies from listing shares on American stock exchanges. What did the Chinese see in negotiator Trump other than an opponent flailing?

Trump also toyed with signaling sympathy for the Hong Kong demonstrators — reportedly as a means to pressure China to give in the trade war. He called on China to offer a “humane” response and talk to the protesters. Ooooh, that must have scared the Chinese.

Whether China honors its agreement of 1984 to let longtime British-ruled Hong Kong manage its own affairs (except for foreign policy and defense) is a matter of indifference to Trump. Presidents past, Democratic as well as Republican, would have undoubtedly defended a capitalistic territory that serves as a bridge between mainland China and the outside world.

Then again, presidents past would also have joined the Trans-Pacific Partnership (now called the Comprehensive and Progressive Agreement for Trans-Pacific Partnership). This multination trade deal was designed to help its members compete against China. It would have been a tremendous boon to American farmers and ranchers.

Trump pulled the U.S. out of TPP his fourth day in office. At one point, he apparently didn’t know China would not be a member. But that may not have made a difference. Why? Trump campaigned promising a trade war, and by golly, he was going to deliver one.

North Korean dictator Kim Jong Un has also observed Trump’s negotiating style of lunging at a foe’s throat and then groveling at his feet. First, he insulted and threatened “Little Rocket Man” with “fire and fury.” Then, needy of Kim’s cooperation, he totally went into reverse. Trump said that he was really tough with Kim, and Kim was tough with him, adding, “and then we fell in love, OK?” The president wisely chose to say that in the safety of a Trump rally.

Let us hope the saxophonist playing our national anthem in Hong Kong still believes in an America separate from Trump. I suspect he does.