Less than a month before Donald Trump sets foot on Canadian soil for the G7, Justin Trudeau鈥檚 chief summit organizer is being forced to defend the viability of the G7 itself.

Trump鈥檚 potential to disrupt the summit 鈥� an international meeting in which the prime minister has invested significant political capital 鈥� is growing larger by the day as his June 8 arrival date in La Malbaie, Que., creeps closer.

Trudeau and his fellow summiteers from Britain, France, Germany and the European Union have already expressed their regrets over Trump鈥檚 decision this past week to withdraw the United States from the Iran nuclear agreement.

Trump was already a G7 outlier on trade and climate change. But now there鈥檚 growing concern that the group itself could fatally fracture, with the U.S. splintering off. The ambassadors from several G7 countries to Canada were forced to address that recently.

Peter Boehm, Canada鈥檚 G7 sherpa, was also confronted with the issue this past week during an unusually tough question-and-answer session at a gathering in Ottawa.

鈥淎re we into a six-plus-one dynamic?鈥� asked Sandelle Scrimshaw, a former foreign service colleague of Boehm鈥檚 during a keynote dinner appearance of the Canadian International Council in Ottawa.

The 63-year-old career diplomat offered a careful, measured reply, but he left open the possibility that the G7, which runs on a consensus basis, simply wouldn鈥檛 be able to reach one next month.

鈥淚f leaders were to agree on everything, there wouldn鈥檛 be a point in having these meetings,鈥� said Boehm.

鈥淵ou try to work out the consensus, and if there isn鈥檛 a consensus there, it鈥檚 clear that you state the obvious 鈥� that we don鈥檛 have unanimity on a particular issue.鈥�

That would mark a repeat of Trump鈥檚 disruptive debut at last year鈥檚 G7 in Italy 鈥� his first foray onto the world of multilateral diplomacy. There was no common ground to be found on climate change.

The leaders鈥� 2017 final communique was accompanied by a footnote that said the U.S. would not join the other G7 countries in reaffirming their commitment to the Paris climate agreement, which Trump also abandoned.

Boehm said there has been careful planning and consulting among his fellow G7 sherpas to ensure a smoother, more successful outcome this time.

鈥淭he sherpas are in contact all the time. I have a very good relationship with all of them and we have each other鈥檚 backs because we鈥檙e in this together.鈥�

Disagreements among leaders are nothing new, Boehm explained.

In fact, the format for their talks will encourage that. They鈥檒l sit alone at a round table and face off with their sherpas sitting behind to take notes and offer advice.

Having new leaders in the room only increases the possibility for disagreement, he added.

鈥淟ast year, there were four new leaders at the table. In my experience, I鈥檝e seen that leaders will come in, they will be a little bit skeptical because they have not done this before and ultimately they see some value in having a frank discussion.鈥�

Canada鈥檚 frank talk will centre on one important theme, Boehm said: the fact that the country needs the international rules-based system to succeed despite the threats it may face.

At the heart of the agenda that Boehm and his fellow sherpas are carefully crafting is how to widen the benefits of the global economy to reach more people 鈥� especially those who feel left out and are feeling a pull towards populist anger.

鈥淩elated to that, of course, is our need to work together, and by that I really mean work together to strengthen the rules-based trading system, and encourage free and fair trade. For us, in Canada, the global trade file is of primordial importance.鈥�

When the leaders take their places at their round meeting table, they will negotiate 鈥� but not in the winner-take-all, 鈥楢rt of the Deal鈥� bare-knuckle bartering style that has been associated with Trump.

鈥淚n order to negotiate effectively, you have to give something up. It鈥檚 identifying that bit that you can give up 鈥� that little bit of sovereignty that you might lose, and realize that it is for the greater good and for unanimity,鈥� said Boehm.

鈥淲e all chip away at that.鈥�

Mike Blanchfield, The Canadian Press