Former NSA Director, General Keith Alexander, has praised Australia's decision last year to ban China's Huawei from bidding for work on the $41 billion national broadband betwork over cyber-security concerns.
The US House Intelligence Committee last year described Huawei as a national security threat and urged American firms to stop doing business with the Shenzhen-based company.
Huawei has denied US allegations that its equipment could be used by Beijing for espionage.
"I think what Australia did on the Huawei decision was tremendous," Alexander said in an interview with The Australian Financial Review, a transcript of which was made available to Reuters ahead of publication.
Alexander, who retired on March 31, also accused former National Security Agency contractor Edward Snowden, who revealed the US government's data collection programs, of being under the control of Russian intelligence agencies.
Civil libertarians in the United States and Washington's allies in Europe were shocked by the extent of US surveillance revealed by Snowden, and a handful of US congressmen have alleged that he was acting at the behest of a foreign government.
Snowden, who fled to Moscow last year, has dismissed the allegations. He expects his temporary asylum status in Russia to be renewed before it expires in summer, according to his lawyer.
"I think he is now being manipulated by Russian intelligence. I just don't know when that exactly started or how deep it runs," Alexander said.
"Understand as well that they're only going to let him do those things that benefit Russia, or stand to help improve Snowden's credibility. They're not going to do things that would hurt themselves. And they're not going to allow him to do it."
In the interview, Alexander described a traditional global security order that has been disrupted by rapid developments in offensive cyber technology, with the potential for unintended consequences rising as a result.
A 2012 cyber attack on government oil company Saudi Aramco believed to have originated from Iran, he said, had been routed through servers in the United States and inadvertently almost disabled a major telecommunications company there.
An attack on South Korea's banking system in 2013 that was believed to have originated in the North, he said, was an example where unintended consequences could accidentally have triggered a shooting war.
"I'm concerned there is a rising chance that individuals and/or nation states miscalculate because they don't know where the red lines are. And this problem of a lack of transparency on red lines, and agreed escalation protocols, is especially acute in cyber-space," he said.
Alexander, who was succeeded by US Navy Vice Admiral Michael Rogers, also signaled his concern over Chinese claims on the oil and gas-rich South China Sea that have increased tension in Asia, arguing that the US should back Japan as a counterbalance Beijing's rise.
"If China continues to act aggressively, I believe we should welcome Japan's increased militarisation," he said.