The US is trying to recruit Germany in its campaign against Huawei.

In a letter sent by the United States ambassador to Germany Richard A. Grenell, the United States has warned Germany that it will reduce intelligence sharing if Germany allows Huawei to build its 5G infrastructure, according to a report from the Wall Street Journal.

Germany reportedly relies on US intelligence to combat terrorism, so the threat of decreased collaboration in this area carries significant weight. However, Germany does not appear swayed by the US' arguments against Huawei, and plans to allow Huawei to bid for the project.

Germany is opening bids for its 5G infrastructure project next week. Huawei is expected to throw its hat in the ring, a prospect that has US officials worried.

The US believes that allowing the Chinese company Huawei to construct and maintain 5G networks will give the Chinese government a backdoor into communications surveillance. Huawei denies these claims. However, a CNBC report found that, under Chinese law, Huawei would be compelled by the Chinese government to assist with government surveillance if the government asks.

Because of this risk, the US has banned the use of Huawei devices in government, and urged its allies to disallow Huawei from building infrastructure. According to the Journal, Grenell's letter marks the first explicit warning about the consequences of awarding Huawei 5G technology.

Huawei and the US have been at odds for years over sanctions violations, IT theft, wire fraud, and security. Most recently, the US is in the process of extraditing Huawei CFO, Wanzhou Meng for fraud and money laundering, part of violating US sanctions against doing business with Iran. More broadly, US intelligence agencies warned against the use of Huawei devices in 2018, and the US government prohibited awarding government contracts to Huawei in a 2018 spending bill.

Huawei isn't taking these accusations lying down. It is suing the US government for prohibiting the use of its devices, saying there is no proof that it is a spy threat. Earlier this March, it took out a full page ad in the Wall Street Journal, telling media (and consumers) "don't believe everything you read."

But the US appears determined to keep Huawei out of the 5G game, whether for security or economic reasons; the Trump administration is trying to win the race to 5G infrastructure against China, even if it is already woefully behind.

The United States' allies don't seem as concerned. Australia and New Zealand have followed the US' lead, keeping Huawei out of 5G infrastructure. But the UK's cybersecurity center has said that it is not concerned about the potential security risks warned against by the US. And, to the ambassador's warning, German representatives told the Journalthat it hasn't seen any evidence of cybersecurity risks, and that Huawei should be allowed to bid for the project in fairness under the law.