In January, Joe Hockey will go from politician (or more accurately ex-politician) to public servant when he becomes ambassador to Washington DC. How cut out for life as a diplomat Hockey is is a little unclear. There was, after all, his peculiar admission that he only took the DC gig because if he’d stayed in politics he would have been obsessed with revenge on those who brought him down (imagine Joe as a Mad Hocks, roaming the political wasteland in the last of the novated lease V8 Interceptors — fully imported, of course).

If the Americans aren’t too worried they’re being used as therapy by a failed Aussie politician, a check of his State Department file might throw up some more interesting quotes. For example, his hosts might not have forgotten Hockey’s attack on Barack Obama in 2009 when he said: “I can’t claim to be an expert on the US economy, but what I do know is that the American people are starting to question Barack Obama’s management of the US economy.”

Given US unemployment has since halved from 10% to 5% under Obama while it rose to over 6% here under Hockey, and the US budget deficit has fallen from 12% of GDP to 2.8% of GDP while Hockey presided over regular deficit blowouts, Joe should probably have stopped at admitting his lack of expertise on the US economy.

Hockey didn’t confine his criticisms of the US to Obama, though: he blamed the US government (and, hint, hint, the Democrats), not Wall St, for causing the financial crisis. “I would argue that they key to the crisis was the market-interfering role that the United States government played in actively encouraging leaders to extend loans to people who were fundamentally unable to service their debts,” Joe opined in 2010.

And while Hockey subsequently changed his tune, let’s not forget his dismissal of the G20 as a “centre-left movement across the world that is trying to run the line that government should be the centre of everything in our lives,” which might raise a smirk or two.

Hockey might also need to be careful about making smalltalk with other ambassadors in DC for fear of reopening old wounds. When Wayne Swan was named world’s best finance minister by Euromoney, Hockey angrily lashed out at the magazine, saying it had awarded “Slovakian ministers, a Serbian, a Nigerian and a Bulgarian. In 2001 there was a Pakistani finance minister. That is quite an extraordinary one, that one.”

What was extraordinary about the Pakistani winner in Hockey’s eyes, he never made clear. He was Shaukat Aziz, who was very close to successive US governments and especially the Bush administration, was lauded for a consolidation of Pakistan’s previously shambolic public finances, and who later serve a full term as prime minister of Pakistan. As for “a Nigerian”, well, that was only one of Africa’s most powerful women, Ngozi Okonjo-Iweala, who became managing director of the World Bank for four years between stints as Nigerian finance minister and foreign minister.

Tread carefully at those Georgetown soirees, Joe. The penalties for a diplomat who regularly sticks their foot in their mouth are much worse than for politicians.