Andrew Cohen is an author and journalist who writes a nationally syndicated column for the Ottawa Citizen. His latest book is "Two Days in June: John F. Kennedy and the 48 Hours that Made Histor y" (Signal/Random House). He is a Fulbright Fellow at the Woodrow Wilson International Center in Washington. The opinions expressed in this commentary are solely those of the author

(CNN) When Prime Minister Justin Trudeau of Canada goes to the White House on Monday, his greatest priority -- and responsibility -- will be forming an easy, effective rapport with Donald Trump.

If Trudeau can create chemistry with an unpredictable President whose agenda and ideas are different from his own, this flying visit will be a success. If they like each other, Trump will be more likely to accept the case for Canada as the most important friend of the United States, with a century and a half of shared history, geography and commerce.

Trudeau is trying to protect Canada from the harshest elements of Trump's commitment to "America First": his protectionist, nativist and semi-isolationist vision of the United States, which could be disastrous for Canada.

Young, optimistic and handsome, Trudeau is the son of celebrated former Prime Minister Pierre Trudeau. Since he led his Liberal Party to a surprising win over the Conservatives in 2015, Trudeau's "sunny ways" and charisma have made him a darling of progressives and an international celebrity.

He got on famously with Barack Obama, who gave him a state dinner in Washington. In gratitude, Trudeau invited Obama to address Parliament in Ottawa, where besotted legislators shouted "four more years!

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No one expects a similar "bromance" between Trump and Trudeau; Trump is unlikely to greet Trudeau with a hug, as he did the Japanese Prime Minister on Friday. The President is older, more conservative and pessimistic; he has different views on Europe, Russia, the United Nations, immigration, refugees and climate change. History suggests a tense relationship: Liberal prime ministers tend to clash with Republican presidents.

Indeed it will take all Trudeau's considerable charm to avoid confrontation. For a country that earns a vast amount of its wealth from international trade, the stakes are high. Canada is a junior partner. When the elephant sneezes, Pierre Trudeau once said , Canada catches cold. To avoid the contagion, the younger Trudeau must show Trump that Canada is a fair trader, a secure source of energy, and a reliable guardian of the northern frontier.

Trudeau will remind Trump that Canada and the United States have the world's largest trading relationship, with some US$2 billion in goods and services crossing the unmilitarized border every day. He will highlight measures taken over the last decade to create "a smart border," facilitating business but deterring terrorists. He will laud Trump's approval of the Keystone XL pipeline (carrying Canadian crude oil from Alberta's oil sands to the United States), which had been blocked by Obama. And he will make much of a big infrastructure project on the Detroit-Windsor border, where Canada is financing a new bridge and customs plaza.

Photos: Meet Justin Trudeau, Canada's Prime Minister Canadian Prime Minister Justin Trudeau took office in November 2015. Skeptics had dismissed the son of former Prime Minister Pierre Trudeau as trading off his father's achievements and famous family name. But pundits in Canada praised the younger Trudeau's campaign and the way he led Liberals to a sweeping victory, with a clear majority in Parliament. See photos from his life and career: Hide Caption 1 of 13 Photos: Meet Justin Trudeau, Canada's Prime Minister The future politician sits in the lap of his mother, Margaret Trudeau, in a car in 1972. He was born in Ottawa on December 25, 1971. Hide Caption 2 of 13 Photos: Meet Justin Trudeau, Canada's Prime Minister Prime Minister Pierre Trudeau takes an outing in Winnipeg, Manitoba, while on vacation in 1977 with his sons, from left, Sacha, Justin and Michel. The elder Trudeau was Canada's Prime Minister from 1968 to 1979 and again from 1980 to 1984. Hide Caption 3 of 13 Photos: Meet Justin Trudeau, Canada's Prime Minister From left, Sacha, Justin and their mother, Margaret, look over Pierre Trudeau's casket in the Hall of Honor on Parliament Hill in Ottawa. The former Prime Minister died September 28, 2000, at age 80. Hide Caption 4 of 13 Photos: Meet Justin Trudeau, Canada's Prime Minister Justin Trudeau is interviewed in his campaign office in Montreal in October 2008, shortly before being elected to represent the Liberals in Parliament from the Montreal electoral district of Papineau. Hide Caption 5 of 13 Photos: Meet Justin Trudeau, Canada's Prime Minister Trudeau addresses youths at Free the Children's National Me to We Day event in Toronto in October 2008. The annual event aims to empower young people to make a difference in their communities. Hide Caption 6 of 13 Photos: Meet Justin Trudeau, Canada's Prime Minister Trudeau greets supporters at the Metro Toronto Convention Centre in April 2013. A short time later, he was elected leader of Canada's Liberal Party. Hide Caption 7 of 13 Photos: Meet Justin Trudeau, Canada's Prime Minister Trudeau works the crowd at the 2015 Toronto Pride parade on June 28. Hide Caption 8 of 13 Photos: Meet Justin Trudeau, Canada's Prime Minister Trudeau visits the Paul Brown Boxfit gym in Toronto in August 2015. Hide Caption 9 of 13 Photos: Meet Justin Trudeau, Canada's Prime Minister After casting his ballot in Montreal in October 2015, Trudeau leaves with his wife, Sophie, and their children, from left, Hadrien, Ella-Grace and Xavier. Hide Caption 10 of 13 Photos: Meet Justin Trudeau, Canada's Prime Minister Trudeau commands the stage in Montreal on after the Liberal Party won the general election in 2015. As the crowd chanted his name, Trudeau said the Liberals won because they listened. "We beat fear with hope, we beat cynicism with hard work. We beat negative, divisive politics with a positive vision that brings Canadians together," he said. Hide Caption 11 of 13 Photos: Meet Justin Trudeau, Canada's Prime Minister Trudeau is sworn into office at Rideau Hall in Ottawa. Hide Caption 12 of 13 Photos: Meet Justin Trudeau, Canada's Prime Minister Trudeau greets Syrian refugees Kevork Jamkossian and daughter Madeleine during their arrival at Toronto's Pearson International Airport in December 2015. The new Prime Minister pledged to take in and resettle 25,000 Syrian refugees in Canada. Hide Caption 13 of 13

Then again, Trudeau is less likely to mention that Canada enjoys a trade surplus with the United States, which buys 75% of its total exports . Or that Canada, a charter member of NATO, spends only 1% of its wealth on defense, suggesting it is free rider.

The good news for Trudeau is that Trump says he has no quarrel with Canada; he does not see Canada as a threat to jobs and security like Mexico. To make this point, Trump sent a representative to a meeting of the Canadian Cabinet in Calgary last month.

Preparing for Trump, Trudeau named a new foreign minister, Chrystia Freeland, an author and former journalist who knows the United States better than her dour predecessor, Stéphane Dion. Trudeau has also consulted Brian Mulroney, the former Conservative Prime Minister, who knows Trump, as well as Canadians who have done business with the President.

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The reality remains that Trump wants to rewrite the North American Free Trade Agreement and could impose a hefty tax on Canada's softwood lumber. His recent executive order banning immigration from specified majority Muslim nations is unpopular in Canada (which has accepted some 40,000 Syrian refugees) but has made national security the signature of his young presidency.

This is where things become sticky for Trudeau: He must balance Canada's interests (trade, investment, jobs) against its values (diversity, open immigration, collective security). Canada is a progressive, moderate society that has adopted universal health care, embraced gay marriage and abortion, and ended capital punishment.

The United Nations, NATO and liberalized trade have been the pillars of Canada's foreign policy since 1945; Canada has imposed sanctions on Russia (Freeland, a Russian speaker of Ukrainian ancestry, is barred from travel to Russia for her criticism of its annexation of Crimea.) Canada supports the Iranian nuclear deal and the Paris Agreement on climate change.

Photos: North Dakota pipeline protests Photos: North Dakota pipeline protests Fireworks lit the sky at the Oceti Sakowin Camp near Cannon Ball, North Dakota on December 4, 2016, after the Army Corps of Engineers halted the Dakota Access Pipeline route. An executive order by President Donald Trump in January allowed work to resume. Hide Caption 1 of 32 Photos: North Dakota pipeline protests Activists embrace after the December halt of the Dakota Access Pipeline route. The $3.7 billion project that would cross four states and change the landscape of the US crude oil supply. The Standing Rock Sioux tribe says the pipeline would affect its drinking-water supply and destroy its sacred sites. Hide Caption 2 of 32 Photos: North Dakota pipeline protests An activist rides down from a ridge on the edge of the Standing Rock Sioux Reservation on December 4. Hide Caption 3 of 32 Photos: North Dakota pipeline protests Activists celebrate at Oceti Sakowin Camp on December 4. An executive order by President Donald Trump in January allows work to resume on the Dakota Access Pipeline, which the activists oppose. Hide Caption 4 of 32 Photos: North Dakota pipeline protests Dan Nanamkin of the Colville Nez Perce tribe drums a traditional song by the Cannonball River in Cannon Ball, North Dakota, on Thursday, December 1. Hide Caption 5 of 32 Photos: North Dakota pipeline protests A procession makes its way down to the Cannonball River to take part in a Native American water ceremony on December 1. Hide Caption 6 of 32 Photos: North Dakota pipeline protests Snow covers the camp on Wednesday, November 30. Hide Caption 7 of 32 Photos: North Dakota pipeline protests A person walks through snow and wind on Tuesday, November 29. Hide Caption 8 of 32 Photos: North Dakota pipeline protests People against the construction of the Dakota Access Pipeline speak at a news conference near Cannon Ball on Saturday, November 26. Hide Caption 9 of 32 Photos: North Dakota pipeline protests A sculpture stands at an encampment where protesters of the pipeline have been gathered for months. Hide Caption 10 of 32 Photos: North Dakota pipeline protests People protest along Highway 1806 as they walk past a sprawling encampment on Thursday, November 24. Hide Caption 11 of 32 Photos: North Dakota pipeline protests A man stands along Highway 1806 on November 24. Hide Caption 12 of 32 Photos: North Dakota pipeline protests In this image provided by the Morton County Sheriff's Department, law enforcement and protesters clash near the pipeline site on Sunday, November 20. Hide Caption 13 of 32 Photos: North Dakota pipeline protests Tonya Stands recovers after being pepper-sprayed by police on Wednesday, November 2. Stands was pepper-sprayed after swimming across a creek with other protesters hoping to build a new camp to block construction of the Dakota Access Pipeline. Hide Caption 14 of 32 Photos: North Dakota pipeline protests Dozens of protesters wade in cold creek waters as they confront local police on November 2. Hide Caption 15 of 32 Photos: North Dakota pipeline protests Tribe members make their way back to their camp on Saturday, October 29. Hide Caption 16 of 32 Photos: North Dakota pipeline protests Cousins Jessica and Michelle Decoteau take part in a protest outside the North Dakota state capitol in Bismarck on October 29. Hide Caption 17 of 32 Photos: North Dakota pipeline protests The burned hulks of heavy trucks sit on Highway 1806 on Friday, October 28, near a spot where Dakota Access Pipeline protesters were evicted a day earlier. Hide Caption 18 of 32 Photos: North Dakota pipeline protests Pipeline protesters sit in a prayer circle as a line of law enforcement officers make their way across the camp to relocate the protesters a few miles south on Thursday, October 27. Protesters had camped on private property. Hide Caption 19 of 32 Photos: North Dakota pipeline protests A protester is arrested as law enforcement surrounds the camp on October 27. Hide Caption 20 of 32 Photos: North Dakota pipeline protests Tires burn as armed soldiers and law enforcement officers stand in formation to force Dakota Access Pipeline protesters off the private land in Morton County. Hide Caption 21 of 32 Photos: North Dakota pipeline protests A protester shows where he was hit by a bean-bag round fired by officers trying to force protesters off the private land. Hide Caption 22 of 32 Photos: North Dakota pipeline protests JR American Horse leads a march to the pipeline site on Friday, September 9. Hide Caption 23 of 32 Photos: North Dakota pipeline protests Native Americans head to a rally at the state capitol in Denver on Thursday, September 8. They were showing their support for members of the Standing Rock Sioux tribe in North Dakota opposting the Dakota Access Pipeline. Hide Caption 24 of 32 Photos: North Dakota pipeline protests People hang a sign near what they say was sacred burial ground disturbed by bulldozers in Cannon Ball. Hide Caption 25 of 32 Photos: North Dakota pipeline protests Marlo Langdeau of the Lower Brule Sioux Tribe joins hundreds of Native Americans for a march near Cannon Ball on Sunday, September 4. Hide Caption 26 of 32 Photos: North Dakota pipeline protests Protesters march on September 4 in opposition to the Dakota Access Pipeline. Hide Caption 27 of 32 Photos: North Dakota pipeline protests Native Americans march to the site of a sacred burial ground on September 4. Hide Caption 28 of 32 Photos: North Dakota pipeline protests Native Americans ride with raised fists to the sacred burial ground on September 4 to protest the Dakota Access Pipeline. Hide Caption 29 of 32 Photos: North Dakota pipeline protests The Missouri River is seen beyond an encampment near Cannon Ball, where hundreds of people gathered to join the protest on September 4. Hide Caption 30 of 32 Photos: North Dakota pipeline protests Flags of Native American tribes from across the United States and Canada line the entrance to a protest encampment on Saturday, September 3. Hide Caption 31 of 32 Photos: North Dakota pipeline protests Phil Little Thunder Sr. attends an evening gathering at an encampment of Dakota Access Pipeline protesters on September 3. Hide Caption 32 of 32

When Trudeau goes to Washington, he will try mightily to make a good impression. He will likely do whatever he can -- rewriting NAFTA, refusing to criticize Trump's policy on refugees, accepting Sarah Palin (as rumored) as U.S. ambassador without complaint -- to keep Canada's biggest customer happy.

But if Trump adopts a foreign policy antithetical to Canada's liberal internationalism, the Prime Minister will come under great pressure from Canadians to stand up to the United States, even at the risk of starting a trade war.

It may be a clash of visions is inevitable, no matter how well the two leaders get on. If so, expect Trump to be vilified in Canada, and for relations with Washington to turn the ugliest since Richard Nixon and the Vietnam War.