The military base in question is the Yulin Naval Base, operated by the People's Liberation Army (PLA) Navy on the southern coast of Hainan Island, facing the South China Sea. Not much is known about the base apart from what little intelligence has been gathered from satellite images and other open-source intelligence.
What is known is that construction on the base began in the early 2000s and that the base is still expanding to allow the docking of warships, including nuclear-capable submarines. (Related: Chinese spy balloon that flew over Montana could be used to carry EMP or nuclear weapons.)
Furthermore, according to information recently shared by the American intelligence community, the Chinese spy balloon was manufactured on this base as part of a sweeping foreign surveillance program run by the PLA. Operations of this surveillance program are centered around the Yulin Naval Base.
According to the Department of Defense, along with the balloon that crossed American airspace, the Pentagon is aware of at least four previous balloons that have flown over U.S. territory.
"This is what we assess as part of a larger Chinese surveillance balloon program," Pentagon Press Secretary Brig. Gen. Pat Ryder told reporters. "This is a program that's been operated for several years."
Analysts are still uncertain just how large China's spy balloon fleet is. But one U.S. official who spoke with reporters suggests there have been "dozens" of espionage flights conducted since 2018.
Known flights over U.S. territory include flybys over Hawaii, Florida, Texas and Guam. Three of the four incidents occurred during the administration of former President Donald Trump but were only recently confirmed to be flights of Chinese surveillance airships.
Before the spy balloon that crossed the U.S. was shot down off the coast of South Carolina, defense officials noted that another spy balloon was observed transiting Central and South America.
According to defense and intelligence officials, these surveillance balloons have been spotted over five continents. Reports indicate that they have collected information on military assets in countries and areas of emerging strategic interest to China – including India, Japan, the Philippines, Taiwan and Vietnam.
"These balloons are all part of a PRC [People's Republic of China] fleet of balloons developed to conduct surveillance operations, which also violated the sovereignty of other countries," said one senior defense official in a news briefing.
"What the Chinese have done is taken an unbelievably old technology, and basically married it with modern communications and observation capabilities," said one official who spoke with reporters on condition of anonymity because of the subject's extreme sensitivity. "It's a massive effort."
The U.S. and its allies who have spotted the balloons within their territories have begun to share specifics with officials, concerned that Beijing may be targeting their military facilities.
This sharing of intelligence is how Japan found out that an aerial orb sighting in 2020 might have been a spy balloon.
"Some people thought this was a UFO," said a Japanese official. "In hindsight, people are realizing that was a Chinese espionage balloon. But at the time it was purely novel – nobody had seen this… So there's a lot of heightened attention at this time."
"There has been great interest in this on the part of our allies and partners," noted a senior White House official. "Many of them recognize that they, too, may be vulnerable or susceptible to this or an object of interest to the PRC."
Learn about other threats to American national security at NationalSecurity.news.
Watch former White House Chief Strategist Steve Bannon and former Defense Intelligence Agency officer Rebekah Koffler discuss below how the intelligence community's focus on Ukraine allowed the Chinese spy balloon to slip unnoticed.