SEOUL, South Korea — One of North Korea’s favorite geopolitical strategies has long been compared to dipping alternately in pools of scathingly hot and icy cold water in a public bathhouse.
Just a week ago, Kim Yo-jong, the only sister and key aide of North Korea’s leader, Kim Jong-un, threatened to kill the country’s agreements with South Korea that were intended to ease military tensions along the border. She called the South Korean president, Moon Jae-in, “disgusting” and “insane.” Then the North blew up the joint inter-Korean liaison office, the first of a series of actions that threatened to reverse a fragile détente on the Korean Peninsula.
On Wednesday, Mr. Kim emerged as the good cop, overruling his military and suspending its plans to deploy more troops and resume military exercises along the world’s most heavily armed border. Hours later, South Korean border guards confirmed that the North Korean military had dismantled loudspeakers installed on the border in recent days as part of its threat to revive propaganda broadcasts against the South.
If the flip-flop seemed disorienting, that was exactly the effect North Korea intended. Over the decades, alternating between raising tensions and extending an olive branch has been part of the North’s dog-eared playbook.
In 2017, Mr. Kim conducted a series of increasingly daring nuclear and long-range ballistic missile tests, driving the Korean Peninsula to the edge of war with the United States. Then he made a sudden switch the next year to a giddy round of diplomacy with President Trump, as well as with Mr. Moon.
Mr. Kim’s grandfather, Kim Il-sung, North Korea’s founding president, proposed reconciliation with South Korea even as he prepared to invade the South to start the 1950-53 Korean War. His father and predecessor, Kim Jong-il, discussed co-hosting the 1988 Summer Olympics with South Korea before North Korean agents planted bombs on a Korean Air Boeing 707 in 1987. The plane exploded near Myanmar, killing all 115 on board.
When the move is toward peace, the change of tack is so dramatic that North Korea’s external enemies often take the shift itself as progress, even though there is no evidence that the country has decided to abandon its nuclear weapons.
“When such a shift comes, the world goes, ‘Wow!’” said Yun Duk-min, a former chancellor of the Korea National Diplomatic Academy. “The world is so impressed that just starting dialogue with the North feels like a major turnaround.”
Mr. Kim’s decision on Wednesday will at least temporarily keep the latest tensions from spinning out of control on the Korean Peninsula. But it also showed that Mr. Kim was calibrating his moves as he sought to reclaim some of the domestic credibility and diplomatic leverage he had lost after his two years of diplomacy with Mr. Moon and Mr. Trump.
Mr. Kim returned from his second summit with Mr. Trump, held in Vietnam in February of last year, without winning a badly needed reprieve from international sanctions that he had promised to his people. Those sanctions have devastated the North’s exports since late 2017.
Mr. Kim began this year by exhorting his people to build a “self-reliant economy” impervious to international sanctions. At the same time, he tried to ease the pain of sanctions by attracting more Chinese tourists and encouraging illegal smuggling.
But that plan sputtered amid the coronavirus epidemic, which has forced the country to shut its borders.
“First and foremost, the economy is the problem for Kim Jong-un,” said Park Won-gon, a professor of international relations in Handong Global University in South Korea. “As the impact of the prolonged Covid-19 epidemic wore heavily on his people’s livelihoods, Kim Jong-un doesn’t have a lot of time left” before he must find a way out, Mr. Park said.
In the North’s playbook, domestic trouble often calls for raising tensions with its outside enemies to win their concessions and also consolidate internal unity.
The North is widely believed to have expedited its nuclear weapons development after it struggled under a devastating famine in the late 1990s. It has pushed its nuclear program as a deterrent against “American invasion,” as well as a tool to extract economic and other concessions from Washington and its allies.
This year, the North’s first target was South Korea and Mr. Moon. North Korea has repeatedly accused Mr. Moon of being so beholden to Washington’s policy of enforcing sanctions that he has reneged on his promise to Mr. Kim to improve inter-Korean economic ties.
Mr. Kim’s sister, Kim Yo-jong, took the lead in the attack against South Korea. But Mr. Kim stayed out of the escalating standoff with the South, giving himself flexibility to change course.
“The brother and sister play the good and bad cop toward South Korea,” said Lee Byong-chul, a North Korea expert at Kyungnam University’s Institute for Far Eastern Studies in Seoul.
Although North Korea has often sounded incorrigibly bellicose, it has proved to be a shrewd strategist capable of judging when to throttle up the tensions and when to pull back on them.
After two South Korean soldiers were injured by land mines in 2015, the South accused the North of planting the devices near the soldiers’ front line guard post. In retaliation, South Korea resumed loudspeaker propaganda broadcasts along the border, bombarding North Korean soldiers with K-pop music and screeds against Mr. Kim. When North Korea fired at the loudspeakers, the South responded with artillery fire. As both sides raised their military alert level, it was the North that first proposed dialogue, and it later expressed regret over the South Korean soldiers’ injury.
In 2018, a North Korean diplomat called Vice President Mike Pence “stupid” and a “political dummy,” threatening to cancel a planned summit between Mr. Kim and Mr. Trump. When Mr. Trump acted first and called off the meeting, North Korea immediately issued another statement saying that Mr. Kim wanted to meet Mr. Trump “at any time.” Mr. Trump was happy to revive the summit plan.
This month too, North Korea has been carefully calculating its maneuvers. Even when its military drew up action plans along the border, the state news media took pains to point out that they would need Mr. Kim’s “ratification.”
Mr. Kim suspended those plans during a meeting of his Central Military Commission on Tuesday. The next day, the North Korean media said the meeting was “preliminary.” The language prompted some analysts to suspect that the commission could hold a regular meeting to have more discussions and potentially reverse course if needed.
“Now that he has succeeded in seizing the attention of Washington, Seoul and Beijing, Kim Jong-un thinks he can pause for a bit to see how they respond,” said Kim Yong-hyun, a North Korea specialist at Dongguk University in Seoul. “By saying that he ‘suspended,’ not terminated, the action plans, he is still keeping the option on the table.”
There were signs that North Korea’s strategy was already working in the South.
As tensions rose on the peninsula, South Korea moved swiftly to ban sending anti-North Korean leaflets across the inter-Korean border. Liberal politicians urged Mr. Moon to persuade Washington at least to allow inter-Korean economic cooperation and humanitarian aid shipments to the North.
There was another reason Mr. Kim hesitated: some of the actions North Korea threatened against the South were tantamount to shooting itself in the foot.
If North Korea follows through on its threat to restart propaganda broadcasts and leaflet distribution across the border, the South would likely respond in kind. North Korea has more to lose, say analysts. The North’s propaganda has little impact on South Koreans, who are far more affluent, while the regime doesn’t have sufficient electricity to raise the volume on its loudspeakers. Cross-border hostilities will also weaken South Koreans’ support for economic or humanitarian help for the North.
But analysts also warned that Mr. Kim may shift his posture again if Seoul and Washington don’t appease the North. As the presidential election in the United States draws near, Mr. Kim could attempt major military provocations to gain leverage with whomever wins the election.
“There may be a pause in provocations or Pyongyang might temporarily de-escalate in search of external concessions,” Leif-Eric Easley, a professor of international studies at Ewha Womans University in Seoul. “But North Korea will almost certainly continue to bolster its so-called ‘deterrent.’”