Li was last seen at the China-Africa Peace and Security Forum in Beijing on August 29. Reporters asked for an explanation at a regular foreign ministry press briefing on September 15, but the spokesperson kept mum.
The day before, a story in the Financial Times said several US government officials and other sources had already concluded that Li has been removed from his position.
The 65-year-old previously headed the Chinese military's Equipment Development Department, and was also responsible for overseeing manned spaceflights and weapons procurement.
In March 2023, he was appointed defense minister and state councilor. The promotion was testament to how much he is — or perhaps was — trusted by President Xi.
US envoy: It's like Agatha Christie
The series of disappearances has drawn global interest. On social media, Washington's Ambassador to Japan Rahm Emanuel likened it to the Agatha Christie whodunnit novel "And Then There Were None."
"Who's going to win this unemployment race?" he quipped. "China's youth or Xi's cabinet?"
Kanda University of International Studies Professor Korogi Ichiro says it's "extremely unusual" for two ministers to suddenly disappear with no explanation.
A Reuters report on September 15 said Li and eight other officials are now under investigation for corruption regarding the procurement of military equipment.
An NHK source points out that the Chinese military procurement process mostly operates within state-owned enterprises. "Fairness and transparency have never been sufficiently enforced. The deeper President Xi digs into this issue, the more corruption he will find."
The source also informed us of an online post by the Chinese military titled "Experts Reviewing Bids for Equipment Procurement for All Armed Forces Seek Clues to Fraud and Discipline Violations."
Professor Korogi points out that it was published just as Li disappeared, adding "it states that the government will investigate corruption since 2017, which is exactly when Li became involved."
Moreover, Hong Kong media say Wei Fenghe, Li's predecessor as defense minister, is now under investigation by an anti-corruption department.
Xi's allies unsafe in their jobs
Chinese political heavyweight Qin Gang was also considered to be a trusted ally of President Xi. But on June 25, he too disappeared from public view while serving as foreign minister.
The government initially put it down to health reasons, but a month later, he was dismissed from his post. Authorities still have not provided an official explanation.
The Wall Street Journal says Qin was removed for adultery and fathering a child in the United States while serving as Beijing's ambassador to Washington. The report went on to say his actions could have compromised national security.
But Professor Korogi says the dismissals could be seen as Xi showing the people around him exactly who's boss.
"Both Qin and Li were promoted because Xi liked them. But apparently, even those who have risen through the ranks can suddenly disappear," he says.
"That's the intention — a tightening of discipline, and a very strong message to the Chinese Communist Party and government. This is a form of intimidation designed to generate more loyalty."
Washington imposed sanctions on Li in 2018 for purchasing weapons from Russia. Korogi says appointing a new defense minister could pave the way for talks with the US secretary of defense.
Expert says confidence in China waning
At the same time, Korogi warns the ramifications of Li's disappearance will extend far beyond the political realm.
"This has created an atmosphere of danger and risk. Foreign investors and wealthy Chinese people are worried. More power is being concentrated under President Xi, but his regime has also become less predictable and transparent."
Xi has not flinched in a years-long crackdown on corruption at all levels — a campaign he describes as "hunting tigers and swatting flies." His rivals have paid the price, but apparently, so are the people who helped him solidify his power.