China’s desire to dominate new wireless technology poses a global threat that should be thwarted by a new, secure network, according to a former Trump administration official whose call for an enlarged US government role caused an uproar last year.

China will gain a capability for mayhem and mass surveillance if it dominates advanced 5G networks that link billions of devices, retired Air Force brigadier-general Robert Spalding said in a memo that was obtained by Bloomberg News.

“The more connected we are, and 5G will make us the most connected by far, the more vulnerable we become,” Spalding, who left the National Security Council last year, said in the memo.

Spalding, who is now retired, confirmed in an interview on Friday his authorship of the memo. He said he wrote it in recent days, and had circulated it to national security professionals whom he declined to identify. A plan he backed last year aroused protests from Republican regulators and lawmakers and wireless companies who said it diminished the role of private companies.

The Trump administration is in tense trade talks with China and has taken steps to restrict its top telecommunications equipment maker, Huawei Technologies Co. The company’s chief financial officer was arrested in December on charges of violating sanctions against Iran.

US government officials and industry executives have long harboured suspicions that Huawei works for Chinese government interests. Huawei has pushed back against the accusations, with a top executive citing “groundless speculation.”

The administration of President Donald Trump and the US wireless industry have embraced the notion of a “race to 5G,” with the main rival being China. Trump in October ordered a national spectrum policy to ensure the US maintains leadership in advanced wireless communications.

Commercial providers are working to develop 5G networks that provide faster links than the current fourth-generation wireless service. The idea is that dramatically higher speeds — 10 or even 100 times faster than current service — will eventually help support self-driving cars, smart appliances and even surgical robots.

Spalding in his memo paints a future headed toward domination by China. Eventually, alternatives to its network technology won’t exist, because other suppliers won’t be able to compete with government-subsidised offerings from Huawei and fellow Chinese gear maker ZTE Corp, Spalding said.

Once China controls the market for internet-connected devices, it will be able “to weaponise cities,” Spalding said in the memo: “Think of self-driving cars that suddenly mow down unsuspecting pedestrians. Think of drones that fly into the intakes of airliners.”

Spalding proposed a network to be built in three years using technology to monitor network devices and “isolate them from the adversary if they become infected.” The network would rely on encryption and a secure supply chain, according to Spalding. His recommendations include “push Huawei and ZTE out of other democracies.”

Spalding didn’t lay out a government role in the new network, which he said could be built by a company with access to enough airwaves. In the interview he said the new proposal was little changed from last year’s, which he said likewise didn’t call for the government to build the network.

A year ago, US regulators and the wireless industry pushed back against Spalding’s plan after it was leaked to the press, with critics saying network construction should come through private efforts. At the time a US official told Bloomberg News unresolved questions included what portion of the project would be taxpayer funded, and whether it would be owned by the government, a private consortium or some combination of public and private entities.

Direct participation by the federal government in building a wireless network intended for commercial use would be a departure from the decades-long tradition of auctioning licenses to telecommunications companies to build their own networks.