Prominent American investor Jim Rogers has warned in a new book that the worst economic downturn in his lifetime is around the corner and that Japan’s future is in jeopardy unless it takes serious steps to deal with staggering debt and a declining birth rate.

In an interview with The Japan Times in Tokyo on Tuesday, the chairman of Rogers Holdings Co. Inc. said that even though the United States and China are poised to reach a trade agreement, any euphoric mood will be temporary. He predicted that U.S. President Donald Trump will ramp up trade wars in earnest to boost his re-election bid in 2020 as the economy slows down.

“Later this year or next, when things are getting bad in the world economy — therefore America is going to start suffering — and Mr. Trump has an election in 2020, he is going to say ‘we got to bash these guys,'” Rogers said. “That’s when Japan, China and other people are going to feel more effects of trade war because he thinks it will help him win the election.”

Rogers jointly established a commodity fund known as the Quantum Fund with influential investor George Soros in the 1970s. He is visiting Japan this week to promote his book, “The Future of Japan and The World That Will Be Read Through the Flow of Money” released in January. The book, available in Japanese, is based on the publisher’s interviews with Rogers.

In the book, he foresees a catastrophic economic downturn within a year or two due to the “unprecedented” level of debt worldwide. The Institute of International Finance reported that global debt soared to $247 trillion in the first quarter of 2018, and Rogers said debt has increased by $75 trillion, or 43 percent, since 2008.

Rogers also portrays a stark future for Japan in the book, pointing to mounting debt, a rapidly dwindling population and a reluctance to embrace immigration.

Japan is set to bring in as many as 345,000 migrant workers in the next five years from April as part of Prime Minister Shinzo Abe’s push to rejuvenate the shrinking labor market. Abe, however, has refused to characterize this as immigration policy, in an apparent attempt to appease part of his conservative base.

Rogers, who believes Japan should accept more immigrants “with caution,” says the move is “better than nothing” to counter the declining population, but says it’s not enough.

“You either have babies, immigrants or declining standard of living. You have decided to have declining standard of living,” he said. “If that’s what Japan wants, do it. … Seventy-thousand immigrants a year for a country of 125 million people doesn’t solve the problem.”

Rogers refrained from directly criticizing Abenomics itself in the interview — he is critical in the book — but he took a swing at its practice of printing money excessively, calling this “lunacy.”

Rogers is known for making provocative statements. In 2017, he said on a financial podcast that “if I were a 10-year-old Japanese, I’d get myself an AK-47 or I’d leave” because of the country’s harrowing economic prospects.

He has persistently made a case for investing in North Korea, predicting in the book that South and North Korea will be unified and describing the Korean Peninsula as the hottest place for investment.

In the interview, he said unification would save money earmarked for defense in South Korea and save lives in both countries. While there might be resistance, he said combining natural resources and labor from North Korea with capital from the South would improve upon the status quo.

While the book takes a grim view of Japan’s future, Rogers hasn’t entirely dismissed the country. He lists tourism, agriculture and the education sector as industries to consider for investment and he proposes spending cuts, lower tariffs and more — but cautious — acceptance of immigration as prescriptions for the country’s problems.

It’s up to Japanese to take his advice, he said.

“I love Japan. It’s one of my favorite countries in the world,” he said. “I just hope you don’t mess it up. You are messing it up now but I hope you’ll get it right.”