In an attempt to push back against attempts to limit its reach in Europe, the Chinese technology giant Huawei threatened legal action against the Czech Republic if its cybersecurity agency did not rescind its warning about the risk the company poses to the nation’s critical infrastructure. On Friday, the Czech newspaper Deník N published excerpts from a letter from Huawei to the head of the Czech cyber agency, Dušan Navrátil, and PM Andrej Babiš threatening legal action.