In this episode, Michelle Grattan speaks with Joe Hockey about his newly-released memoir titled Diplomatic. 

Hockey, treasurer in the Abbott government and former Australian ambassador to the United States, picked early that Donald Trump had a good prospect of becoming president and reached out to his team, something that went down badly at the time with the foreign affairs bureaucracy back in Canberra.  

But Hockey says: "Diplomacy is just about human relations. It's countries dealing on the same basis with each other as human beings. So you're never going to get on well with someone you don't know. You're actually going to have to engage."

Of Trump's successor, Hockey says: "I think Joe Biden has aged quite a bit in the presidency.  He's only been president for just over a year.  He's really shown he hasn't had the energy that you would expect of someone as president of the United States."

Also, "he's run a very left wing agenda, and that's completely stunned – completely stunned – middle America, because they thought he was a safe, middle-of-the-road sort of person.

"America is just not tuned into that. They're not buying that."

Speaking about the differences between US and Australian politics, Hockey highlights the significance of compulsory voting in this country. "I think the challenge in the United States is, you know, firstly, you try and get your own people to vote. And the more extreme you are, the more you villainise, and radicalise your opponents. It's easier to get people to come out and vote for you if they're against something.

"We don't have that battle for the extremes, and I think that's really, really important," he says.

"The political ads and what people say about each other in the United States has no filter, has no boundaries. And as a result, it becomes more fractious, becomes much more aggressive. And I think it's really, really important that proper defamation laws [exist] that allow someone to go in and protect their reputation so that people cannot make ridiculous, false accusations against others."

And Hockey's prediction for May 21? "I think it's just too close to call, really. I genuinely feel that both parties have a pathway to victory. And then, as so often the case, as events unfold during the campaign, we'll get a clearer picture of which way [...] the events are breaking."