Should Donald Trump be elected US President, Australia should tear up the ANZUS alliance. Malcolm Turnbull or Bill Shorten could be prime minister by this time next year, but this is a simple bipartisan choice. If Trump wins the keys to the White House, there will be no need for a congratulatory phone call. Just get the clock ticking on the 12-month waiting period required to formally withdraw from the treaty.
Australia would be well served to maintain diplomatic ties - at least with New York, Seattle and San Francisco - and get ready for a big spike in visa applications for permanent residency. 
Sure, jokes are easy. The Huffington Post has made light by covering Trump's candidacy in the "entertainment" section of the news website.
But be serious for a moment. How will the world react if Trump is the champion? What will China's Xi Jinping think of Trump's "I beat China all the time" philosophy? Or Ban Ki-moon, when Trump, the billionaire property mogul from New York, insists he could have personally renovated UN headquarters for less than what it was?
Talk about awkward. You have to love this exchange with Malcolm Turnbull when The Guardian recently asked about the prospect of a Trump victory.
Question: So, speaking of oversize characters, what kind of president do you think Donald Trump would make?
Turnbull: "[Laughs] Hmmm."
Q: Well he's the frontrunner.
Turnbull: "I, er, I think I won't make any comments on respective American candidates."
A very politic answer - and much more careful than the episode when Labor's Wayne Swan, who bluntly declared while Treasurer in 2012 that "cranks and crazies" had taken over part of the Republican party. Or John Howard, warning in 2007 that al-Qaeda in Iraq would "pray" for a Barack Obama victory.
But Trump? The candidate who would assert: "The concept of global warming was created by and for the Chinese in order to make US manufacturing non-competitive."
The concept of global warming was created by and for the Chinese in order to make U.S. manufacturing non-competitive.
??? Donald J. Trump (@realDonaldTrump)      November 6, 2012
Who warns: "Tremendous infectious disease is pouring across the border. The United States has become a dumping ground for Mexico and, in fact, for many other parts of the world."
Citizens in a democracy have a sovereign right to elect whomever they choose, but when it's the US, with all its attendant power and boastful claim to global leadership, the rest of the planet tends to have an opinion.
Turnbull was too polite, missing the chance to sound a gentle alarm. Comic John Oliver might chide we did elect Tony Abbott, but are they truly alike? And what a difference in consequences. One conservative think-tank assessed Trump's tax plan would strip $11 trillion from the US federal budget, and a colleague jokes maybe Trump would have to scrap the military anyway?
Of course, there is a long way to go in the race to be the next president. There is a sense Trump is pumping his legs faster and faster on a treadmill and at any moment he will lose control and fly right off.
But not yet he hasn't. For three months, Trump led the polls in his bid to win the Republican nomination, with all the extra scrutiny and attention that brings. That's far longer than most pundits and political hardheads would have credited.
There is reason to be cautious and point to history. Howard Dean, the upstart governor from tiny Vermont, led the Democratic race in 2004 with a populist campaign, until a strangled "Yeeeeaaaagh" to a packed room of supporters was broadcast and his campaign imploded.
But breaking conventional rules is what Trump is all about. "You could see there was blood coming out of her eyes," Trump said after being critically quizzed by a Fox News journalist in   August. "Blood coming out of her wherever."
If an ridiculous slur about women and menstruation hasn't finished him, let alone his racial jibes about blacks or Hispanics, or his refusal to believe Obama is American by birth, maybe the man is gaffe-proof in the electorate.
What may be just as significant is how Trump's antics have also set a tone for other candidates. Ben Carson, whose folksy wisdom includes "a lot of people who go into prison straight and when they come out they're gay" (he apologied) and a belief Christians built Egypt's pyramids to store grain (he's standing firm), has edged over Trump in the polls. And maybe now Carson is set to crash over doubts he was really offered a place at West Point military college, as so long claimed, with support to flow back to Trump.
So what? Opinion polls are meaningless fodder for media until the tally of the first vote on   February 1 in Iowa (  February!), and state by state thereafter. There is also more conventional wisdom that, in the US primary system, to win a party nomination drives candidates to extremes to attract the vote of their party base, only to steer back to the centre for the main event.
This skew is also evident in the Democrat race. Although lacking the incandescent and fevered rhetoric of the other side, another Vermont politician, Bernie Sanders, has pitched to the Left and done his best to disrupt what most assume is Hillary Clinton's manifest destiny to be the candidate, and then president.
All the conventional wisdom could turn out to be true, and surely - surely - the Trump campaign will fizzle and fold, along with Carson's and that of any other clown. Republican Marco Rubio has also jumped in standing in recent weeks, favoured more as another of the "establishment" candidates (and featuring the same band of backroom advisers who urged the invasion of Iraq).
But tempting though it may be to simply assume a natural sensibility will prevail, it might also be worth taking a little time to ponder just how Trump's plans to "make America great again" will reflect on friends. Like Australia.
Daniel Flitton is a senior correspondent.