Before a Chinese spy balloon was discovered in the United States, American officials said a rival power may have used advanced technology to surveil U.S. military sites.
WASHINGTON — The Chinese spy balloon floating over the continental United States caused deep concern on Capitol Hill because it came on the heels of a classified report to Congress, which outlined incidents of American adversaries using advanced technology to spy on the country. A classified report to Congress last month discussed two incidents of a rival power conducting aerial surveillance with what appeared to be unknown cutting-edge technology, according to U.S. officials. The surveillance probably was conducted by China, according to two American officials familiar with the research, despite the fact that the report did not attribute the incidents to any country. The intelligence agencies called unidentified aerial phenomenon focused on several incidents believed to be surveillance. Some of the incidents involved balloons, while others involved quadcopter drones. The Chinese government said on Friday that the Chinese balloon discovered this week in the United States was mainly for weather research. American officials said it was considered a collection device, but not one that could gather sensitive information that advanced Chinese reconnaissance satellites already collect.
The incidents could potentially indicate the use of technology that was not fully understood or publicly identified, but officials said that further investigation was needed. Some of the 171 reports that have not been attributed to balloons, drones or airborne trash appear to have demonstrated unusual flight characteristics or performance capabilities, and require further analysis. Officials cautioned that imperfect radar and sensor readings could cause confusion, making an ordinary object appear to be something threatening.
The Pentagon released images of some of the suspected surveillance incidents that were initially unexplained. The images showed green triangles in the air taken from two different Navy exercises. Pentagon officials said the triangles were simply small drones at a congressional hearing last year. The use of night-vision gear had made them look otherworldly. In one incident a Chinese ship was in the vicinity, despite the fact that the drones had not been officially attributed to any country. It is not clear how strong the evidence is that China is using an advanced technology that the United States does not possess. Some American officials are skeptical that China would expose some of its most advanced technology in any surveillance activity that could be detected by the United States. The surveillance balloon caused outrage on Capitol Hill. Some officials said that information about adversarial spying contained in the classified report on unidentified aerial phenomena had already caused concern.