A white something that hovers high above the northwest of the US state of Montana causes a lot of frowns not only in the USA. The Pentagon is convinced that the flying object is a spy balloon from China. There have been similar incidents in the past, but never over such a long period of time. The Wall Street Journal wrote that it was one of the most aggressive maneuvers by the Chinese secret services in years.

The balloon flies “at an altitude well above commercial air traffic and poses no military or physical threat to people on the ground,” the official said. However, because falling debris poses a danger to people on the ground, shooting it down is currently too dangerous; Secretary of Defense Lloyd Austin accordingly advised President Joe Biden against such a measure.

However, action was taken immediately “to prevent the collection of sensitive information”. F-22 fighter jets took off to observe the balloon. Air traffic in Montana’s largest city, Billings, has been temporarily suspended.

However the US Department of Defense assumes that the balloon has only a “limited additional benefit for reconnaissance work”. After all, satellite images should reveal much more to Beijing.

An overview of what we know so far – and what not.

The object (probably) started in China, passed the Aleutian chain of islands near Alaska and then flew over northwest Canada, US media reports. Canadian intelligence services were working with American partners and were on the lookout for a “possible second incident,” the Canadian Department of Defense said in a succinct statement.

The current flight path has been taking the balloon over Montana and “a number of sensitive locations” since Wednesday, according to the Department of Defense. What is meant is probably, among other things, a military base in the north of the sparsely populated state. Malmstrom Air Force Base is one of three air force bases storing ICBMs armed with nuclear warheads. According to the Wall Street Journal, around 150 Minuteman III nuclear missiles are stationed here alone.

A spy balloon is surveillance technology (such as cameras or radars) that is suspended under an inflatable umbrella and scouts a specific, usually militarily sensitive, area. The unpowered flying objects usually fly at an altitude of between 24,000 and 37,000 meters, well above civil air traffic.

Spy balloons were used in the US Civil War in the 1860s. At that time, soldiers from the Union States wanted to spy on the Confederates with binoculars. They sent signals back using Morse code or with a “piece of paper tied to a rock,” John Blaxland, a professor of international security and intelligence studies at the Australian National University, told the British Guardian. The modern, unmanned versions were booming during the Cold War. Back then, the US used hundreds of them, Peter Layton, a fellow at the Griffith Asia Institute in Australia, told US news channel CNN.

But why should a military superpower like China still rely on such supposedly antiquated methods at all? In fact, satellites have been “the measure of all things” over the past few decades, says Blaxland. However, these are no longer untouchable – modern lasers and kinetic weapons always pose a threat.

Balloons, on the other hand, are much more difficult to spot than you might think. “They have a very low signature and little to no emission, making them difficult to detect with traditional situational awareness or surveillance technologies,” military expert Blake Herzinger told CNN.

Plus, balloons have another, more mundane benefit: they’re cheap, and they’re only getting cheaper thanks to smaller and lighter spy gear. Sending a satellite into orbit, on the other hand, still costs millions upon millions of dollars.

In addition, balloons can observe a larger area over a longer period of time. Not only do they move much slower than their pompous relatives. In contrast to satellites, balloons can be controlled (to a limited extent) by on-board computers that use wind currents. Their comparatively low flight altitude should also be more of an advantage than a disadvantage. “They could be collecting signal data, in other words, they’re looking at our cell phone traffic and our radio traffic,” Cedric Leighton, a former US Air Force colonel, told the US broadcaster. Satellites are simply too far away to intercept such data.

Such balloons are likely to be used far more frequently in the future. This is also due to the fact that it is now becoming very cramped in near-Earth space. As the magazine “Politico” reported last summer, the US military is now investing more in balloons.

China’s government says it is following the reports, but warns against hasty speculation. “We collect and check the facts,” Foreign Ministry spokeswoman Mao Ning told press representatives in Beijing. “We hope that both sides will treat the matter with a cool head.” It is not helpful to speculate or hype the matter until it is clear what happened.

In any case, the balloon has already broken one of the most important rules of espionage: it has been discovered. However, Beijing should have expected it, experts are sure. After all, the US monitors its airspace meticulously.

It is possible that they wanted to show Washington how mature Chinese military technology has become. In that case, finding the balloon would be part of the plan. Another explanation: the whole thing is an accident. Beijing may just have lost control of the balloon.

“China’s flagrant disregard for US sovereignty is a destabilizing measure that needs to be addressed,” tweeted Kevin McCarthy, Republican Speaker of the House. Other conservatives were also critical and called on the Biden administration to act immediately.

In fact, the timing for such an incident is far from ideal and is likely to exacerbate tensions between the two superpowers.

Anthony Blinken is expected in Beijing on Sunday – the first visit by a US Secretary of State to China in around six years. The aim is to smooth the waves in the enormously cooled relationship between the two superpowers. Blinken is to meet with President Xi Jinping.

The United States announced on Thursday that it would increase its military presence in the Philippines to assist the island state of Taiwan in the event of a Chinese invasion.

Sources: US Department of Defense; “New York Times”; “The Guardians”; CNN; “Bloomberg”; with DPA and AFP