At MWC, the White House sent a team from the State, Commerce and Defense Departments, as well as the chairman of the Federal Communications Commission, Ajit Pai, to make the case against Huawei.

Nobody appeared to be won over. Vodafoneʼs chief executive, Nick Read, defended Huawei at a news conference, repeating a not-so-subtle swipe at the United States that criticism of Huawei wasn’t “fact based.” Officials in the United Arab Emirates, a typically reliable American ally in the Middle East, seemed to agree. On Monday, just as MWC was starting, the country’s state-owned wireless carrier announced a deal with Huawei to build the 5G network there.

Perhaps sensing a momentum shift, Huawei has ratcheted up its opposition to the American campaign. On Monday, a Huawei executive, Vincent Peng, said cybersecurity was a “technical challenge, not a political challenge.” The next morning, Guo Ping, the company’s rotating chairman, said the United States had a more checkered history of espionage than Huawei, referring to the whistle-blower Edward J. Snowden’s disclosures in 2013 of an internet surveillance program by American spy agencies and their allies.

Huawei is a relatively boring company. While it has branched out to become one of the world’s largest manufacturers of smartphones, it primarily makes the gear needed to make phone networks work. It’s the kind of infrastructure people rely upon but don’t give much thought.

But the debate is worth following. Huawei foreshadows conflicts about important emerging technologies such as artificial intelligence, in which China is developing an expertise that the United States and its allies are likely to view as an economic and security threat.

In other news:

■ The other week, I averaged three hours and 12 minutes of screen time per day. I feel somewhat proud of this figure, pathetically, because it was down from some of my more frightening recent averages, which occasionally topped — not sure I should admit this — five hours. Kevin Roose described his detox experience in a memorable column about how we can assert control over our digital lives. I have a long way to go.

■ Life is even worse than we thought for Facebook moderators who are paid $15 an hour to review the internet’s most horrific material. After Casey Newton’s must-read investigation was published this past week in The Verge, I like the idea that all Facebook employees should have to spend a month doing this job.