OXFORD – The United States and some of its allies have acted decisively to exclude the Chinese technology company Huawei from their national markets, yet they continue to ignore the similar threat posed by Facebook and other US digital giants. Democratic governments must now be equally decisive in dealing with this home-grown danger.

LONDON, May 16: China’s Huawei poses such a grave security risk to the United Kingdom that the government must reconsider its decision to give it a limited role in building 5G networks, a former head of Britain’s MI6 foreign spy service said on Thursday.