TOKYO -- Choe Ryong Hae, a secretary of North Korea's ruling Workers' Party of Korea and the reclusive state's point man on relations with China, has disappeared from the public eye.
Choe was absent from a recent state funeral for a political heavyweight and former comrade of Kim Il Sung, North Korean leader Kim Jong Un's late grandfather and the country's founding leader.
Rumors about Choe, widely seen as North Korea's de facto No. 2 or No. 3 figure, being purged have spread around the world.
China played an unwitting though key role in the banishment, a new twist in the behind-the-scenes power struggle underway in North Korea.
The latest political drama involving Choe began when he visited China as Kim Jong Un's special envoy to a massive military parade in Beijing on Sept. 3.
Choe traveled from Pyongyang to Beijing via Shenyang, in the northeastern province of Liaoning. During his one-and-a-half-day stay in China, he exchanged views with two senior Chinese officials on how the two countries could improve their soured relations.
The Chinese officials were Wang Jiarui, head of the Chinese Communist Party's International Department, and Liu Yunshan, a member of the Politburo Standing Committee, the party's top decision-making body. Liu is ranked fifth in the party's hierarchy.
Wang is also said to have gone to Shenyang to greet Choe there.
"Choe Ryong Hae failed," a source said. "He couldn't achieve the mission given to him by Kim Jong Un. Kim took the latest action against Choe as punishment."
So what was Choe's mission?
It was to invite Chinese Premier Li Keqiang, No. 2 in the Communist Party's hierarchy, to watch a military parade in Pyongyang on Oct. 10, together with Kim.
The military event was to mark the 70th anniversary of the founding of the Workers' Party of Korea, which Kim helms as its first secretary.
Pyongyang's desire for Li's presence at the military parade reflected the bitter rivalry between North and South Korea, which technically remain at war. The 1950-53 Korean War ended in an armistice, basically a cease-fire.
On Sept. 3, China held a massive military parade in Beijing to commemorate the 70th anniversary of its victory in "the war of resistance against Japanese aggression" as well as "the world anti-fascist war." Chinese President Xi Jinping and his South Korean counterpart Park Geun-hye stood together on the Tiananmen rostrum to watch the extravaganza.
It was a humiliating scene for North Korea's Kim. Xi is the top leader of a traditional ally, while Park is, well, the enemy. North Korea believes that its relations with China have been "cemented in blood" since Chinese troops fought in the Korean War on the North's behalf.
North Korea was aware it would probably be impossible to get President Xi to attend its military parade. But it at least wanted Li, China's No. 2 figure, to attend the event in a bid to regain some of the diplomatic ground lost to South Korea.
Choe, who attended the military parade in Beijing as Kim's special envoy, was also North Korea's de facto No. 2 or No. 3 figure, on par with China's Li.
China immediately rejected North Korea's request; accepting it would have brought huge risks.
Around that time, North Korea was showing signs of preparing to test-fire a ballistic missile and was also said to be eager to conduct its fourth nuclear test.
Had North Korea taken such provocative actions in defiance of global pressure during or shortly after a Li visit to Pyongyang, China would have lost face and had its international standing damaged.
China's relations with North Korea deteriorated sharply in 2013, after the North's third nuclear test. China has called for denuclearizing the Korean Peninsula.
Pyongyang was somewhat aware from the beginning that getting Li to pay it a visit was a tall order, so Choe had prepared a Plan B.
He asked that Yu Zhengsheng rather than Li make the trip. Yu serves as chairman of the National Committee of the Chinese People's Political Consultative Conference, the country's top political advisory body, and is No. 4 in the Communist Party's hierarchy.
Yu is also in charge of the issue of ethnic minorities in China, including ethnic Koreans living in Jilin Province's Yanbian Korean Autonomous Prefecture and elsewhere.
But China also rejected this.
China now enjoys extremely good diplomatic ties with South Korea. Ethnic Koreans in China also have close economic relations with South Korea. Under these circumstances, China did not want to provoke South Korea by sending a high-ranking official, especially a figure who is in a position like Yu's, to attend Pyongyang's military parade.
China eventually agreed to dispatch Liu Yunshan, its No. 5 figure, to North Korea. Liu is in charge of party affairs, and it was thought he could improve ties between the Chinese Communist Party and the Workers' Party of Korea.
Kim was not happy. Liu was not even on Choe's list of possible Chinese invitees. Yet Kim had no choice but to accept China's offer.
Liu became the first member of the Chinese Communist Party's Politburo Standing Committee to visit North Korea since 2010, when Zhou Yongkang visited Pyongyang.
Zhou would later fall victim to Xi's sweeping anti-corruption campaign. In June, he was sentenced to life in prison after being found guilty of bribery and other crimes.
Liu visited Pyongyang with a personal letter from Xi to Kim. Liu and Kim talked on Oct. 9 and watched the military parade in the North Korean capital together the following day.
Despite wearing a smile, Kim was still deeply disgruntled about China's response to North Korea's invitations to the parade. Senior officials of the Workers' Party of Korea were aware that Kim had harbored a desire to greet Chinese Premier Li.
Pyongyang had to put the blame on someone, otherwise Kim's authority would have suffered and the country's future diplomacy could have been affected. Since Choe was given the mission to recruit Li, he bore the brunt of that blame.
Under Kim's dictatorship, any high-level official can be abruptly purged. The job of serving as the country's point man on relations with China is particularly perilous, as exemplified by the execution of Jang Song Thaek, Kim's uncle, at the end of 2013.
The ancient kingdom of Koguryo, or Goguryeo, ruled northeastern China and the northern part of the Korean Peninsula from the 1st century BC to the 7th century.
This history continues to fill North Koreans with pride. Unlike in South Korea, many people in North Korea deem playing second fiddle to China unacceptable.
The question now is whether Choe has any chance of making a political comeback.
Choe's father is a North Korean hero and former comrade of Kim Il Sung. The Choe family has long made significant contributions to the Kim family. It would be unwise for Kim Jong Un to discard Choe out of pettiness. Doing so could also infuriate China, since Choe acted as Liu Yunshan's counterpart during the Chinese official's Pyongyang visit.
Choe's whereabouts provide a clue as to his fate.
Some media reports have said Choe was sent to a farm in the North Korean countryside for re-education. But one source denied the reports. "Choe is now conducting a political study in Pyongyang," the source said. "It is possible for him to make a political comeback sometime in the future."
In fact, Choe has once already returned to the political stage after disappearing from the public eye in the past.
China sees the latest drama involving Choe as little more than political kabuki; it believes he will stage a comeback.
"Choe's father and Kim Il-sung were comrades who fought together in the northeastern part of China before North Korea was founded," one Chinese diplomatic source said. "Choe is the right person to serve as North Korea's point man on relations with China."
North Korea's antics regarding China and Choe are ongoing. It remains unclear whether Choe will act as North Korea's point man on relations with China again. The answer may crystallize by the end of this year or may remain foggy for another year or two.
In time, China and North Korea will implement diplomacy with an eye on Kim Jong Un's first China visit. By rebuilding its ties to North Korea, China can gain a new diplomatic card to play as it deals with the international backlash to its island-building program in the South China Sea.
Aside from the timing, attention will be focused on whether Kim will break with tradition and become the first North Korean leader to travel to Beijing by air. His grandfather and father, Kim Jong Il, both shied away from doing so, making the journey by rail.
In any case, Choe's fate and Kim making a trip to China, which would be a major diplomatic event for North Korea, would be closely related to each other.
Katsuji Nakazawa is a winner of the prestigious Vaughn-Ueda prize for international journalism. He joined The Nikkei in 1987 and is a former chief of The Nikkei's China Headquarters. This column is part of weekly series investigating what is happening at the center of President Xi Jinping's administration.