For Guo Ping, chairman of Chinese technology group Huawei, Monday was a day like any other. In a speech in the southern Chinese city of Shenzhen, he painted a rosy picture of how Huawei’s technological prowess and leadership in 5G telecoms equipment would transform the company’s hometown into a global digital showcase city.

Hours later, that promise was shattered — shot down by an announcement from the US government that it will use the global dominance of American technology to cut off all supplies of semiconductors to Huawei. 

In boardrooms and government offices around the world, the new rules sparked frantic discussions about whether the move would deliver a fatal blow to the $122bn company, how quickly Huawei might fold, and what the collapse of the world’s largest telecoms equipment provider would mean for networks in 170 countries that run on its hardware.