Sidney Rittenberg knows a thing or two about China. During World War II, he learned fluent Mandarin as a U.S. Army linguist, worked in China, left the Army and joined the Chinese Communist Party. He became friends with Mao Zedong and spent 16 years in solitary confinement—as Mao’s prisoner.

We recently spoke to Rittenberg about his experiences in Maoist China, his imprisonment and why he became disillusioned with the party. In his 93 years, he’s seen China and America at their best … and their worst.

Now as tensions between Washington and Beijing grow, Rittenberg worries that American officials are returning to old habits of seeing China as a mysterious and hostile power. The former apparatchik thinks this is a grave mistake.

On July 9, Gen. Joseph Dunford told the Senate Armed Services Committee that China—and Russia, too—present the greatest threat to American security.

“They present the greatest existential threat,” Dunford said. “If you look at their behavior, it’s nothing short of alarming.”

China is rapidly upgrading its military and expanding its navy. The United States is undergoing a “Pacific pivot,” shifting military forces to the region and its strategic waterways. To be sure, Rittenberg blames both Washington and Beijing for the veritable arms race between the two countries.

But in the second part of our extensive interview, Rittenberg warned that a potential conflict with China would be disastrous … and bloody. He doesn’t believe it would be a war America could win. “We’re not very good at learning,” he said.

In any case, he believes the United States and China have far more—and better—reasons to work together than to fight. He argues that this has been the case historically, even when Washington and Beijing didn’t have diplomatic relations at all.

Complicated Ties:

Rittenberg derives his views from his relationships and experiences. He’s a retired academic and ran a consulting business for American firms seeking to do business in China. He also twice translated for Mao during the communist leader’s interactions with the U.S. government during the 1940s.

Back then, Mao made several overtures to the Harry Truman administration, even as his rebels fought the U.S.-backed regime of Generalissimo Chiang Kai-shek. Mao’s reasons were pragmatic—he wanted normal diplomatic relations with the United States so he wouldn’t have to depend on Joseph Stalin.

As Rittenberg sees it, Washington missed a golden opportunity to exploit a growing rift between the Soviet Union and China’s future communist leaders—and perhaps avoid future wars in Korea and Vietnam. Or at least, make those conflicts far less costly.

Besides, the Soviets were stingy. Following the Chinese civil war, the communists requested a $300 million loan from Moscow. Instead, Stalin gave them $4.4 million. Another time, Mao told Rittenberg of an attempt to buy smelting equipment from the Soviet Union. Stalin slapped a condition on the sale—the Chinese had to buy Russian rocks to go with the equipment.

“Mao told Stalin that there were plenty of rocks in China, but Stalin said they came as a set,” Rittenberg recalled with a laugh. “He said China couldn’t have one without the other.”

China’s communist leadership soon locked Rittenberg away at Stalin’s insistence—the Soviet dictator thought he was a Western spy. Mao didn’t release Rittenberg until 1955, after Stalin’s death.

Sino-Soviet relations didn’t improve when Nikita Khrushchev took power, either. The new leader continued Stalin’s propensity to condescend to the Chinese, which offended them. “I remember once seeing Khrushchev come out of that room purple faced, madder than you can hardly imagine,” Rittenberg recalled of a meeting between the Khrushchev and Mao.

During one visit, the Soviet leader told Mao he expected the Chinese to invite Soviet technical advisers to sit in during all committee meetings. When the Chinese leader told him they would instead brief the Russians on whatever decisions they made, Khrushchev protested.

“Khrushchev told [Mao] ‘all our comrades in Eastern Europe do it this way,’” Rittenberg recalled. “Mao told him, ‘I know what happens in Eastern Europe, that’s why we’re not going to do that.’”

By the 1960s, Khrushchev had recalled most Soviet advisers.

Pres. Richard Nixon—who ironically rose to prominence as an ardent anti-communist—finally pushed the United States to recognize that communist governments weren’t in lockstep with each other.

He made China a priority, arguing that “there is no place on this small planet for a billion of its potentially most able people to live in angry isolation.” His 1973 visit led to a historic thaw in relations between the two powers.

Best Frenemies:

“We’ve taken a strategic position with every president since Nixon, that a strong China is good for America,” Rittenberg said. “Despite what you hear, relations on the ground are actually very good.”

He said that post-Nixon, American leaders have generally welcomed Chinese prosperity as an opportunity for mutual growth and healthy competition. He’s not wrong. Dozens of U.S. government agencies regularly hold high and mid-level talks with their Chinese counterparts—a level of engagement Rittenberg argued America has with few world governments.

In 2007, Gen. Peter Pace—one of Dunford’s predecessors—accepted a Chinese invitation to tour the country. He became the highest ranking American military official to visit China since the 1940s.

It was an important visit. Six years earlier, a Chinese J-8 fighter jet collided with a U.S. EP-3 spy plane, killing the Chinese pilot and forcing the American plane to make an emergency landing on Hainan island. It was a significant international incident that chilled relations.

But in the years since Pace’s visit, the U.S. and Chinese navies have teamed up for disaster relief exercises and port visits. Both navies have sent warships to patrol for Somali pirates in the Gulf of Aden. During the summer of 2014, a Chinese hospital ship attended the U.S.-led RIMPAC exercise in Hawaii for the first time—although Beijing brought an uninvited spy ship along for the trip.

Later that year, a handful of American, Chinese and Australian troops participated in a survival skills in an Australian jungle for weeks during Exercise Kowari 2014.

“There’s a lot of talk about rethinking our China strategy today,” Rittenberg said. But he said he’s wary of a “containment” strategy in regards to Chinese power. He’s also skeptical of increased U.S. security talks with China’s neighbors such as India and Vietnam. “We seem to be trying to form a sort of anti-China alliance.”

His major point—a war with China would be a tragedy for everyone involved, and that the U.S. military’s technological superiority may prove less decisive in a war with China than many Americans might expect.

“The last war we truly, decisively won was Grenada,” Rittenberg asserted. He argued that the Persian Gulf War’s bloody aftermath and the U.S. military’s continuing entanglements in Iraq calls into question the effectiveness of Operation Desert Storm. “And now you want to fight China?”

Ultimately, Rittenberg thinks that most of the tough talk is just that—talk. As he sees it, Beijing and the Washington have too many shared strategic interests. Both fear political instability and terrorism. Both benefit from a globalized economy. Chinese and American companies have ties that are too deep—and profitable—for either side to want to act on their harsh rhetoric.

But he thinks business may also drive anti-China fears in America. Specifically the arms business. “I think a lot of this is about selling weapons,” he said. “I think we’re trying to have China be a friend and an enemy at the same time.”

He asserts that fear of Chinese power is good for the American defense lobby, keeps military spending high and justifies the acquisition of high priced systems like the hot—but controversial—F-35 Joint Strike Fighter.

Assertive China:

Rittenberg readily admits that China is far from blameless for the buildup of tensions. The United States has been able to increase security ties and arms sales to China’s neighbors in part because of Beijing’s own increasing arms buildup and willingness to flex its military muscles.

“I think the ‘assertive’ is the word people use today when we talk about China,” Rittenberg said. “And China has been quite assertive.”

In May 2014, China moved an oil rig to an area of the South China Sea claimed by Vietnam. The Vietnamese coast guard ordered the rig to leave, and the two sides got into a scuffle—which escalated to a Chinese coast guard ship ramming a Vietnamese vessel. Back in Vietnam, angry protesters attacked Chinese citizens and businesses.

Beijing ultimately agreed to move the rig, but then moved it back in June 2015. Such brazen moves have made several Southeast Asian nations, including Vietnam and the Philippines, understandably wary.

In June 2015, U.S. Defense Secretary Ash Carter announced that Hanoi would purchase new American patrol boats for its coast guard. Vietnam has also strengthened ties with the Philippines—a key U.S. ally in the region.

“We might get back some bases in the Philippines and maybe some naval docking in Vietnam,” Rittenberg said. “But the Southeast Asian countries are never going to be true allies to us or China.”