A surveillance balloon flying at high altitude is not sophisticated spyware. But the Chinese device discovered earlier this week over the northwestern US state of Montana has proved effective as a diplomatic irritant between the world’s biggest economies.
Secretary of State Antony Blinken canceled a trip to China in response to the intrusion, even though Beijing claimed it was a “civilian airship used for research” that had been diverted.
The Pentagon announced earlier this week that it was tracking the balloon over Montana, where the US has nuclear intercontinental ballistic missile silos. At the time, it said President Joe Biden had decided to shoot it down because of the risk to citizens. On Saturday, the US shot down the balloon off the East Coast.
Earlier, the Pentagon had said that its decision not to shoot down the balloon reflected the fact that it provided little information to China that it could not obtain from satellites. Canada said it was tracking the balloon in conjunction with the US, but was also tracking “another possible event”.
What is a spy balloon?
First deployed during the French Revolutionary Wars, balloons manned by spies with binoculars were used to detect enemy troop movements during the American Civil War.
They were used extensively during the Cold War, as the US and the Soviet Union sought ways to monitor each other’s military.
Lacking propulsion, they are subject to the vagaries of air currents. But cameras, radar and radio equipment can be placed in modern versions of low-cost equipment.
Why would one be used?
Vast improvements in satellite technology and the proliferation of spy satellites in recent decades, as well as the increasing use of unmanned drones, have made surveillance balloons technically largely obsolete. But they are still being used, especially for non-military observation.
The Pentagon said the balloons did not give China a capability that was beyond its spy satellites, but military and intelligence analysts said the balloons’ slow speed and high altitude – they typically operate at about 80,000 feet, which is far greater than that of commercial airliners – allowing them to record over a larger area and take in more detail than satellites in orbit.
They are harder to detect than metal drones or aircraft using conventional anti-surveillance equipment such as radar, while they can remain in the air for weeks, allowing longer assessments of activity on the ground.
In 2019 it was revealed that the Pentagon was experiencing its own spy balloon renaissance, a pilot plan to “provide a continuous surveillance system to detect and deter drug trafficking and homeland security threats”. was starting
What could China hope to achieve?
The Pentagon said the balloon was detected in US airspace after crossing Canada. Other states in the region, including Montana and North Dakota, have a few bases from which the US would launch nuclear weapons in the event of war. A US official said, “Obviously, this balloon is intended for surveillance.”
Malmstrom Air Force Base, home to the US Air Force’s 341st Missile Wing and silos for 150 intercontinental ballistic missiles, is located in a state of Montana otherwise known for mountains and prairie.

US officials said the Pentagon had taken steps to prevent the balloons from recording critical information.
Accusing each other of espionage is nothing new for the US and China. Beijing has long claimed that US ships and aircraft are conducting surveillance near its borders. The US insists that its surveillance operations are conducted in international waters and airspace. Last year, Admiral John Aquilino, the head of the US Indo-Pacific Command, flew a spy plane over the South China Sea.
Other spy balloons have been spotted over US territory in the past – although this usually did not last long.
Some analysts suggested that the balloon was either mistakenly directed towards the US, or was intended to be discovered as a means of reminding Washington to be on its guard.

Balloon in the sky over Montana earlier this week © Chase Doc / AFP via Getty Images
Blake Herzinger, a non-resident fellow at the American Enterprise Institute, said on Twitter before China offered its explanation that “we need to at least consider the possibility that it was a mistake,
“Beijing is not mad. Sending a balloon over the continental United States to collect something they certainly could do in secret from space is a completely unnecessary risk,” he said.
What is the potential diplomatic impact?
The cancellation of a two-day trip to Blinken is already a major consequence. Washington’s chief envoy was expected to meet Chinese President Xi Jinping on a trip that would have made him the first Biden administration cabinet secretary to visit China and the first secretary of state to visit the country in more than five years.
Relations between the superpowers are already bad. Blinken’s trip was part of efforts to stabilize tensions following talks between Biden and Xi in November. The leaders agreed at that meeting that they should try to set a floor on the relationship, which has fallen to its lowest level since the establishment of diplomatic relations in 1979.
Some Republicans in Congress, including Tom Cotton, a senator from Arkansas, had seized on the news before calling on Blinken to cancel his trip. He has also criticized the White House for allowing such intrusions.
Michael McCaul, Republican chairman of the House Foreign Affairs Committee, said that Blinken “should have gone to let Chairman Xi and his government know that his military adventurism will no longer be tolerated”.
“I do not think so [Chinese] Leadership understands just how big of a political deal this spy balloon is becoming in DC. Bill Bishop said, a US-China analyst. ,[It] intensifies an already rapidly darkening mood [Capitol] Hill.”
what happens now?
A Chinese statement issued on Friday said: “The Chinese side regrets the unintended entry of the airplane into US airspace Surprise, The Chinese side will continue to communicate with the US side and properly handle this unforeseen situation,
The US has previously said it expressed its displeasure to China through various channels, but it was unclear how Washington might try to play down or defuse the issue with Beijing. Canada summoned the Chinese ambassador to Ottawa on Thursday to register its objection.