WASHINGTON — Rick Woldenberg thought he had come up with a sure-fire plan to protect his Chicago- area educational toy company from President Donald Trump’s new taxes on Chinese imports.

“When he announced a 20% tariff, I made a plan to survive 40%, and I thought I was being very clever,” said Woldenberg, CEO of Learning Resources, a third-generation family business that has been manufacturing in China for four decades. “I had worked out that for a very modest price increase, we could withstand 40% tariffs, which was an unthinkable increase in costs.”

His worst-case scenario wasn’t worst-case enough. Not even close.

Trump upped the ante with China, raising the levy to 54% to offset what he said were China’s unfair trade practices. Then, enraged when China retaliated with tariffs of its own, he upped the levies to 145%.

Woldenberg reckons that will push Learning Resources’ tariff bill from $2.3 million last year to $100.2 million in 2025.

“I wish I had $100 million,” he said. “Honest to God, no exaggeration: It feels like the end of days.”

It might at least be the end of an era of inexpensive consumer goods in America. For four decades, and especially since China joined the World Trade Organization in 2001, Americans have relied on Chinese factories for everything from smartphones to Christmas ornaments.

Late Friday, the Trump administration said it was excluding electronics, including smartphones, from the current reciprocal tariffs. But it still could levy new or different tariffs on electronics at a later date.

By pausing some tariffs for dozens of countries for 90 days and exempting electronics from some tariffs, Trump also gave away something to his main rival, Chinese leader Xi Jinping, with whom he has engaged in a game of chicken that risks decoupling the world’s two biggest economies and turning the global economic order upside down.

Xi learned that his adversary has a pain point.

As reckless and ruthless as Trump may seem to some parts of the world, in Xi and China, he is squaring off with a leader and a party state that have a history of single-minded pursuit of policies, even when they resulted in economic and human catastrophe.

As tensions have risen over the past decade, Mexico and Canada have supplanted China as America’s top source of imported goods and services. But China is still No. 3 — and second behind Mexico in goods — and continues to dominate in many categories.

China produces 97% of America’s imported baby carriages, 96% of its artificial flowers and umbrellas, 93% of its children’s coloring books and 90% of its combs, according to a report from the Macquarie investment bank.

Over the years, U.S. companies have set up supply chains that depend on thousands of Chinese factories. Low tariffs greased the system. As recently as January 2018, U.S. tariffs on China averaged just over 3%, according to Chad Bown of the Peterson Institute for International Economics.

“American consumers created China,” said Joe Jurken, founder of the ABC Group in Milwaukee, which helps U.S. businesses manage supply chains in Asia. “American buyers, the consumers, got addicted to cheap pricing. And the brands and the retailers got addicted to the ease of buying from China.”

Now Trump, demanding that manufacturers return production to America, is swinging a tariff sledgehammer at the U.S. importers and the Chinese factories they rely on.

“The consequences of tariffs at this scale could be apocalyptic at many levels,” said David French, senior vice president of government affairs at the National Retail Foundation.

The tariffs are also likely to push up prices. The University of Michigan’s survey of consumer sentiment, out Friday, found that Americans expect long-term inflation to reach 4.4%, up from 4.1% last month.

“Inflation’s going up in the United States,” said Stephen Roach, former chairman of Morgan Stanley Asia and now at Yale Law School’s China Center.

It’s not just the size of Trump’s tariffs that has businesses bewildered and scrambling; it’s the speed and the unpredictability with which the president is rolling them out.

On Wednesday, the White House said the tariffs on China would hit 125%. A day later, it shot up to 145%, to include a previously announced 20% to pressure China to do more to stop the flow of fentanyl into the United States.

China in turn has imposed a 125% tariff on the U.S. effective Saturday.

“There is so much uncertainty,” said Isaac Larian, the founder of MGA Entertainment, which makes L.O.L. and Bratz dolls, among other toys. “And no business can run on uncertainty.”

His company gets 65% of its product from Chinese factories, a share he is trying to winnow down to 40% by the end of the year. MGA also manufactures in Cambodia, India and Vietnam, but Trump is threatening to levy tariffs on those countries, too, after delaying them for 90 days.

Larian estimates the price of Bratz dolls could go from $15 to $40 and that of L.O.L. dolls could double to $20 by this year’s holiday season.

Even his Little Tikes brand, which is made in Ohio, is not immune. Little Tikes depends on screws and other parts from China. Larian figures the price of its toy cars could rise to $90 from a suggested retail price of $65.

The New York Times contributed.