As Australia’s ambassador to the US, Mr Hockey was key in calming tensions within the Trump administration when Mr Downer’s unwitting role in sparking the FBI probe came to light in late 2017.
Mr Hockey, who was known to be close to US president Donald Trump, said the importance of the Five Eyes partnership could not be understated.
“I can’t tell you how important the Five Eyes partnership is for us. US intelligence has been instrumental in thwarting nine of the 13 disrupted terrorist attacks in Australia,” he said.
“Our role in Five Eyes is more valuable than ever because of the increasing importance of the Indo-Pacific. We are not under threat in Five Eyes, but we could have been.”
Asked how Australia’s role in the intelligence sharing alliance could have been under threat in the past, Mr Hockey said: “Australia was under pressure on Five Eyes because of the whole Downer issue.”
“The FBI and CIA were under profound attack and the Downer issue could have gone really badly for us… I don’t want to say anything more about that.”
Mr Downer famously met with Trump campaign staffer George Papadopoulos at a London wine bar in 2016, where he was told the Russians had a dirt file on rival candidate Hillary Clinton in the form of hacked Democratic Party emails. He later relayed the information to Canberra via a diplomatic cable and then to the Chargé d’Affaires of the US embassy in London.
In a break with diplomatic protocol, Australia allowed the FBI to conduct a highly sensitive interview with the then-UK High Commissioner in London just hours after the probe opened in August, 2016, just as the US election was heating up.
Mr Trump was said to be infuriated by the Downer revelations, asking his Attorney-General William Barr to investigate how the Russia probe started and telling reporters “I hope he looks at Australia”.
A report by US Inspector General Michael Horowitz later concluded that Downer’s intervention was pivotal in the FBI’s decision to launch “Operation Crossfire Hurricane”, but did not include any criticism of his or the Australian government’s actions.
John Blaxland, professor of international security and intelligence studies at the Australian National University, said revelations that US intelligence had been so integral to thwarting terror plots in Australia underscored the importance of the information sharing arrangement between the two countries.
“The current dynamics have undoubtedly generated unease and concern, and a desire to double down on ensuring the United States recognises what they’re doing for us,” he said.
“Most people don’t appreciate the depth, breadth and intimacy of those ties – how much it is an arrangement of mutual benefit.”
Australia, the US, Britain, Canada and New Zealand are members of the “Five Eyes” alliance that shares highly sensitive intelligence with each other.
Anthony is foreign affairs and national security correspondent for The Sydney Morning Herald and The Age.
Peter Hartcher is political editor and international editor of The Sydney Morning Herald.