Scott Morrison resides at the Harold Holt end of the Liberal Party when it comes to relations with the leader of the free world in Washington, DC.

Holt is remembered for an ad lib he made during remarks at the White House in July, 1966.

Otherwise prosaic comments became big news when Holt picked up and used a Democratic Party slogan for President Lyndon Johnson, saying he was “All the way with LBJ”.

Morrison’s enthusiasm for current White House occupant Donald J. Trump is well known. While Trump was curious initially about how Morrison had come to power in a party-room ballot, the pair bonded after the Australian was re-elected against the odds in May last year.

Trump views Morrison as a kindred spirit. Photo: Getty

Trump regarded Morrison as a kindred spirit – sparking at the mention of the “quiet Australians” who the Prime Minister nominated as the source of his widely unpredicted win.

This manly romance was sealed with a full-blown state visit last September which featured a bells-and-whistles official dinner and a shared stage at a factory opening-cum-election rally at a facility developed by Australian billionaire Anthony Pratt.

The bond was visceral.

Trump treated Morrison to all the bells and whistles in 2019. Photo: Getty

Morrison now has another invitation for September this year, to attend a global leadership meeting at the Camp David presidential retreat north of Washington.

Trump was originally planning to host the G7 summit at his Florida Doral golf resort but backed off after what he called “irrational hostility”.

The G7 this year had been clouded by the COVID-19 crisis, but this past week Trump revisited the idea at the height of the worst urban unrest across US cities since 1968.

Trump, who had already flagged the venue would be Camp David if the summit went ahead, surprised everyone by proposing a larger gathering adding four nations beyond the core seven.

The USA, Great Britain, France, Germany, Italy, Canada and Japan would be joined by South Korea, India, Australia and Russia – identified as “a nice group of countries” by the President.

“I don’t feel that as G7 it properly represents what’s going on in the world. It’s a very outdated group of countries,” said Trump.

Morrison accepted the invitation without hesitation – as did South Korea’s Moon Jae-in and India’s Narendra Modi. The Russians say they are still considering Trump’s offer of a seat at the summit.

While the invitation and quick acceptance in Canberra was painted as a feather in Australia’s diplomatic cap and something Morrison could hardly decline, there are compelling reasons why the prime minister should have at least hesitated when Trump called.

Primarily, one of the key agenda items Trump has flagged – ganging up on China over the COVID-19 pandemic and a range of economic and strategic issues – has “nothing in it for Australia” stamped all over it.

We have already felt the ire of Beijing because of initial loose talk in relation to a World Health Organisation inquiry into the origins and handling of the pandemic.

Chinese displeasure was soon felt with tariff and non-tariff responses hitting barley and beef exports.

China has signalled it regards Trump’s expansion of the G7 – which deliberately excludes Beijing – as unfriendly, warning it would “not benefit” the US.

For Australia to get caught up in intensifying America-China tension would be a diplomatic own goal with no upside.

Next, there’s the vexed question of Russia’s likely presence.

The Russian government has refused to take responsibility for the shooting down of MH17. Photo: Getty

Many observers see Trump’s invitations to Australia, South Korea and India as cover for his main aim in adding chairs around the G7 table – to get his friend Vladimir Putin in the room.

Trump wanted Russia at the 2021 G7 in France but was overruled by the host, Frence’s Emmanuel Macron. Australia was one of a handful of nations the French president invited as observers to be part of a global discussion about inequality.

Australia has unfinished business with Russia over the downing of the Malaysian Airlines jet MH17.

Russian operatives have been found guilty of launching the missile that blew the passenger jet out of the sky in mid-2014 but the Kremlin refuses to admit liability or accept the Dutch court’s judgment.

It would be unacceptable for Morrison to sit across the table from Putin.

Lastly, if the G7 September meeting goes ahead (it is not that certain, with one key leader, Germany’s Angela Merkel, indicating she might not attend, ostensibly because of the virus) there’s the issue of US presidential politics.

The meeting would be some six or seven weeks before the November 3 election and Trump will doubtless use it as part of his campaign.

If he continues to lag in the polls as badly as he is doing now, it is anyone’s guess what stunt he might pull to throw a September surprise on the campaign trail.

There is no good reason for Australia to attend the G7 in September.

With any luck it will be postponed until after the November election – and then the Democratic Party contender, Joe Biden, might well be the host. That would change everything.