Hong Kong CNN Business  — 

The arrest of Huawei’s chief financial officer caps a terrible year for the Chinese tech company.

Canadian authorities said late Wednesday they had detained Meng Wanzhou at the request of the US government, which wants her extradited on unspecified charges.

A spokesperson for Huawei said the company was “not aware of any wrongdoing” by Meng, the daughter of company founder Ren Zhengfei.

Huawei, which makes smartphones and equipment for telecommunications networks, has already found itself on the defensive this year after a number of countries blocked wireless carriers from using some of its products, citing national security concerns.

Here’s a look at Huawei’s biggest setbacks of 2018.

AT&T deal crumbles

Huawei started the year on a low note, when hopes that AT&T (T) would sell its smartphones in the United States were crushed in early January. (AT&T owns CNN’s parent company, WarnerMedia.)

The deal would have been Huawei’s first partnership with a major US mobile carrier, but it “fizzled out at the last minute,” a person familiar with the matter said at the time.

Huawei continues to face opposition in the United States, partly because of concerns that its technology could be used by the Chinese government to gather intelligence — allegations Huawei has repeatedly denied.

US intelligence agencies warn against using Huawei phones

Another body blow came in February, when US intelligence agencies said that American citizens shouldn’t use Huawei phones.

Top US intelligence officials appeared before the Senate Intelligence Committee and testified that Huawei and ZTE (ZTCOF), another Chinese smartphone maker, pose a security threat to American customers.

Huawei said at the time that it was “monitoring developments” in Congress, but declined to comment directly on the committee hearing.

Best Buy (BBY), one of the few places where Americans could find Huawei devices, said in March that it would stop selling them.

UK security officials flag ‘new risks’ from Huawei

Top UK security officials have warned that they can only provide “limited assurance” that Huawei equipment poses no threat to national security.

In an annual report published in July, a government oversight panel said that “shortcomings in Huawei’s engineering processes have exposed new risks in the UK telecommunication networks.”

On Wednesday, UK telecoms group BT (BT) said it would not buy equipment from Huawei for the core of its next generation wireless network.

BT also said it would remove existing Huawei technology from the heart of its 4G network within two years.

Australia bans Huawei from its 5G networks

Huawei’s ambitions of becoming a global leader in 5G technology took a major hit in August, when Australia blocked Huawei from providing 5G equipment for the country’s wireless networks.

The Australian government said that the involvement of telecom equipment suppliers “who are likely to be subject to extrajudicial directions from a foreign government that conflict with Australian law” could mean the country’s wireless carriers are unable “to adequately protect a 5G network from unauthorized access or interference.”

Huawei called the decision “an extremely disappointing result for consumers.”

The company strongly denies that its products pose a security risk. It says that its equipment is trusted by customers in 170 countries and by 46 of the world’s 50 largest telecommunications companies.

American allies urged to block use of Huawei equipment

The Wall Street Journal reported in November that Washington is urging its allies to stop using Huawei telecommunications equipment because the company poses a security threat.

Sources familiar with the discussions told the Journal that US officials are pushing countries with American military bases to ban the use of Huawei equipment from their wireless and internet networks. That includes countries like Germany, Italy and Japan.

Huawei said in a statement at the time that it was “surprised by the behaviors of the US government detailed in the article” and that “such activity should not be encouraged.”

Last week, New Zealand blocked a top telecom firm from using Huawei equipment for its 5G mobile network.

Spark, the country’s largest telecommunications company, said government officials told the company that using Huawei’s 5G equipment “would, if implemented, raise significant national security risks.”

It wasn’t all bad news

Huawei may be under fire in the United States and elsewhere, but it has powered ahead in some other markets.

The company, which isn’t listed on a stock exchange, reported 325.7 billion yuan ($47.4 billion) in revenue for the first half of 2018, an increase of 15% over the same period a year earlier. It didn’t disclose profit figures.

The company told CNN last week it has signed more than 20 commercial contracts for 5G equipment and technology, but didn’t disclose the companies or countries involved in those deals.

In a statement Wednesday, Huawei said it had signed a memorandum of understanding with Portugal’s leading wireless operator Altice to develop 5G services.

Still, analysts warn the United States may not be done with Huawei. They point to a ban imposed earlier this year by the US government that prevented ZTE from buying vital parts for months.

“The worst case scenario here is something like the denial order slapped on ZTE that would bar US companies from supplying Huawei, and it depends on US companies for critical components,” said Paul Triolo, the head of global tech policy at risk consultancy Eurasia Group.