American pro-wrestlers Bob "The Beast" Sapp, left, and Jon Andersen, right, leave the arena after a pro wrestling exhibition, Saturday, Aug. 30, 2014, in Pyongyang, North Korea. (Wong Maye-E/AP)

North Koreans are not exactly used to seeing 300-pound Americans in tiny black underpants with “strong man” emblazoned across the rear.

So they audibly gasped when Jon Andersen, the professional wrestler from San Francisco with muscles that look set to burst out of his skin, appeared on a floodlit stage in a Pyongyang stadium Saturday night, with music declaring, “He’s a macho man,” blaring from the sound system.

Women clasped their hands over their mouths when, seconds later, an even bigger American wrestler, Bob Sapp, emerged in a white sequin-and-feather cape to the theme song from “2001: A Space Odyssey.”

Once in the ring, Andersen exhorted Sapp to “kill ’em!” as the pair took on two Japanese wrestlers, picking them up and throwing them on the ground.

Unlikely as it may seem, these two fearsome Americans, together with their compatriot Erik Hammer, are part of the latest effort to bring about more harmonious relations between North Korea and the outside world.

North Korean women, dressed in traditional Chogori watch a pro wrestling exhibition, Saturday, Aug. 30, 2014 in Pyongyang, North Korea. North Koreans got their first look at pro wrestling in about 20-years when former NFL lineman Bob "The Beast" Sapp, and 20 other fighters from around the world took to the ring for an exhibition in Pyongyang. (Wong Maye-E/AP)

Indeed, many of the 13,000-plus carefully selected North Koreans in the audience laughed out loud when, in a move that did not look entirely spontaneous, one of the Japanese wrestlers ducked and Andersen kicked Sapp square in the chest instead. Another American miscalculation, their laughter seemed to say.

The violent spectacle — complete with flashing lights and heavy metal music — was part of the Pyongyang International Pro Wrestling Games, a weekend of martial-arts-related events organized by Antonio Inoki, the Japanese wrestler-turned-politician who promotes “peace through sports.”

Famous in the United States for his 1976 fight against Muhammad Ali, Inoki is on a personal mission to help improve ties between the communist state and its former colonial master, and especially to help resolve decades-old abduction cases.

The three Americans are among the 20-odd wrestlers participating in his two-day event here, in which sport is used to provide contact that politics does not currently allow.

In an event every bit as surreal as basketballer Dennis Rodman’s visits to Pyongyang — although North Korean leader Kim Jong Un did not attend this tournament — some residents of the most isolated nation on Earth were exposed to an entirely foreign concept.

At the start, they did not seem amused. Most sat implacably, clapping politely at what seemed like the appropriate moments.

But some began cheering as a sequined-mask-wearing Japanese wrestler called Ultimo Dragon, having had his head wedged between his opponent’s legs for most of his match, got up from the mat and triumphed. North Korea loves an underdog.

Then they laughed as a Japanese wrestler trash-talked his opponent and chuckled at some of the more obviously choreographed moves. Some North Koreans even got out their cellphones — a relatively new piece of technology here — and took photos.

But almost everyone looked mystified when four Japanese women, one in a red velvet leotard and another in a Rastafarian-themed poncho with a picture of a marijuana leaf on it, took to the ring and pulled each other’s hair, kicked their opponents in the head, and engaged in other actions at odds with the North Korean ideal of femininity.

As one foreign diplomat in the audience tactfully put it, the show provided a glimpse of the outside world that North Koreans don’t usually see.

Nothing in North Korea is left to chance, and such events — even in the capital, home to the political class most loyal to the Kim family — are strictly controlled. It is highly likely that these North Koreans were carefully selected by the government and well prepared for the cultural contamination of the show.

One 16-year-old boy’s response to a journalist’s question could have come straight from the central propaganda department.

“I want friendship between Japan and North Korea, and I hope that this event will contribute to better relations,” the chubby-cheeked high school student said when asked whether he’d ever seen anything like this kind of wrestling.

Although the event was more about relations between North Korea and Japan, at a time when the United States is practicing “strategic patience” with Kim’s government and there is next to no official contact between the two countries, the fact that such an American event took place in Pyongyang is notable.

Hammer said he hoped he had dispelled some North Koreans’ ideas about Americans, who are often referred to as “mi-je-nom,” or “cunning American bastards,” in the state literature.

“I’m being very careful here,” the wrestler said as he jumped rope to prepare for his fight. “I would never want to do anything to embarrass my country.”

Proponents of cultural exchanges say non-political interaction can help improve relations between foes and ease the isolation of closed societies.

While skeptical about the prospects of better ties, Evans Revere, a former U.S. diplomat with a long career of dealing with Pyongyang, said such events could help with mutual understanding.

“We always hope that events like this will open the curtain up a little wider and that we will be able to develop some insights into what’s happening inside North Korea,” Revere said. “And even more importantly, that people in North Korea will be exposed to what’s going on outside.”

The gradual thaw between the United States and China in the 1970s was helped along by ping-pong matches, while performing-arts exchanges with the Soviet Union helped bring down the Iron Curtain. But cultural diplomacy with North Korea is even harder than it was with China because there is no political will supporting such efforts, said John Delury, a professor at Yonsei University in South Korea who visited Pyongyang with Google’s Eric Schmidt last year.

“I don’t think these exchanges can improve official relations,” Delury said.

Adam Cathcart, an expert on North Korea at Leeds University in England, agreed, saying the lack of official contact between the countries meant there was no way to capitalize on a more favorable environment.

“Like an artery, if nothing is moving through it, it’s not actually a channel but is an unhealthy wall,” Cathcart said. “If there is no mechanism for follow up, if one’s interlocutors change . . . then you are forced to start over at every stage and the notion of ‘progress’ via such visits is illusory.”

For now, the propaganda was working in one direction at least.

After 24 hours in Pyongyang — staying in the country’s fanciest hotel and eating meals specially prepared for foreign guests — Andersen said he had seen nothing of the missile-testing, hunger-inducing, repressive place shown on television.

“When I get back to the United States, I’m going to straighten out all my family and friends,” the gigantic wrestler said, declaring that he’d seen the real North Korea. “It’s just classic American ignorance about the rest of the world.”