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The Winter Olympics, which officially open Friday in PyeongChang, South Korea, are taking place in the shadow of a geopolitical showdown. Seoul and Pyongyang are approaching the event as an opportunity for a tentative thaw in one of the world's most frozen conflicts. But the United States is not so enthused about Seoul's baby steps toward rapprochement.

These include a number of cuddly Olympic gestures. A joint South and North Korean women's hockey team will compete for a medal; their “national anthem” will be the beloved Korean folk song “Arirang.” The countries' delegations will march together in the opening ceremonies under a joint “unification” flag depicting a map of the Korean Peninsula. The North Koreans even dispatched a ferry bearing an all-female cheerleading squad — vetted for both looks and ideology — that may draw heavy attention from international photojournalists.

More significant, a high-level North Korean delegation including Kim Yo Jong, the younger sister of Kim Jong Un, arrives Friday. It will be the first time a member of the Kim dynasty has crossed the heavily fortified border with the South.

Kim is expected to have lunch with South Korean President Moon Jae-in the day after the Opening Ceremonies. Meanwhile, Vice President Pence will attend the event with the father of Otto Warmbier, the American college student who died last year after apparent abuse and torture in North Korean detention. The two guests neatly illustrate the differences simmering between Seoul and Washington: Moon, a liberal who came to office last year, has pushed for greater engagement with Pyongyang, while the Trump administration continually vows a campaign of “maximum pressure” on North Korea in a bid to curb its nuclear weapons program.

During a stop in Japan on Thursday, Pence promised that the Trump administration “will soon unveil the toughest and most aggressive round of economic sanctions on North Korea ever.” As one former State Department official said to my colleague Anna Fifield, the administration's agenda “constitutes a frontal assault on Moon's North Korea policy.”

My colleague Josh Rogin, who was in the media pack traveling with the vice president, confirmed the dissonance between Washington and Seoul. “I asked Pence directly how he planned to deal with Moon’s public desire to build off of the North-South Olympic engagement,” Rogin wrote. “Pence said the Trump administration wants the warming of relations with North Korea to end when the Olympic flame is extinguished. 'We also reaffirm our commitment to continue well beyond the Olympics — when the Olympics are long a distant memory — to continue to isolate North Korea economically and diplomatically,' Pence said. It’s the message Pence has been repeating at every stop on his Asia trip; the Trump administration does not support a diplomatic breakthrough at this time.”

A diplomatic breakthrough is unlikely, indeed. South Koreans who oppose engagement with Pyongyang have burned the North Korean flag and images of Kim Jong Un in the streets of Seoul. On Thursday, despite whispers that Pence might meet with North Korean officials on the sidelines of the Opening Ceremonies, North Korea's state mouthpiece declared that Pyongyang had “no intention” of allowing such a tête-à-tête. Already, there are concerns in other corners over how Moon's government has accommodated the North Korean delegation, even at the risk of violating international sanctions in place against Pyongyang.

“This seems to be a canny and tactical move by North Korea,” said Robert Kelly, a professor of international relations at Pusan National University in South Korea, to Fifield. “All this aura of good feeling is fine, but is it going to translate into anything substantive at the negotiating table? I hope it works, but previous efforts have been two steps forward, three to the side, then one back.”

But the South Korean government ultimately just wants everything to go off without some kind of upsetting incident.

“I think things will remain calm on the peninsula until at least the end of March,” said J. James Kim, a research fellow at the Asan Institute for Policy Studies, speaking at a telephone briefing organized by the Woodrow Wilson International Center for Scholars. “That’s largely because after the Olympics, you have the Paralympics coming, and there’s North Korean participation in the Paralympics as well. … We will see if things will heat up again with the resumption of the joint exercise [between the United States and South Korea] in April, and the key will be whether Washington decides to engage in talks with North Korea without putting conditions.”

With the Trump administration disinclined to engage in substantive talks — and the North Koreans unlikely to relinquish their game-changing nuclear arsenal — it is unclear what kind of positive step could realistically be taken. But the worst-case scenarios, as outlined by Vox's Yochi Dreazen in a chilling piece, ought to disabuse any American official of any idea of heading in the opposite direction toward armed conflict.

“With so many artillery pieces and rocket launchers trained on Seoul, Kim has the ability to quickly blanket the densely packed city with huge amounts of nerve agents. The human toll would be staggeringly high,” Dreazen noted. “The military historian Reid Kirby estimated last June that a sustained sarin attack could kill up to 2.5 million people in Seoul alone, while injuring nearly 7 million more. Men, women, and children would very literally choke to death in the streets of one of the world’s wealthiest and most vibrant cities. It would be mass murder on a scale rarely seen in human history.”

Bruce Bennett, a senior researcher at the Rand Corp., suggested that defeating the Kim regime would require the United States to commit at least 200,000 troops to an all-out ground war. “By way of comparison, that would be significantly more troops than the U.S. had in either Iraq or Afghanistan at the peaks of those two long wars,” Dreazen wrote. And that is before even contemplating the implications of a nuclear war.

The prospect adds a bit more meaning to the fleeting display of Korean unity as the games get underway.

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