Keep U.S., Canada ties strong.

Justin Trudeau’s attendance at a White House state dinner, the first by a Canadian prime minister in 19 years, is a good time to reflect on the importance of the relationship between the two North American neighbors. The U.S. and Canada share much more than a border.

The two nations also share common values, cultures and interests, perhaps as closely as any two countries in the world.

On trade, security and energy issues, the interests of Canada and the U.S. are inextricably linked, and President Barack Obama should be working to strengthen those bonds in ongoing discussions with Trudeau.

Canada is not only America’s largest trading partner, but because we occupy the same continent it is also the country it relies on most to assure mutual security. David Inserra and Nicolas Loris of the Heritage Foundation offer a four-point priority list for building better cooperation with Canada.

First, the analysts recommend making cross-border travel and trade simpler and more secure. As Detroiters know, before the September 11 terrorist attacks moving from Detroit to Canada and back was an effortless enterprise. Detroit’s automakers in particular enjoyed a seamless link between their facilities in the United States and those in Canada.

Terrorism fears changed that, perhaps too much. Inserra and Loris recommend "looking to further expand entry and exit information sharing, expanding pre-clearance and trusted traveler and trader programs, and using bodies like the Regulatory Cooperation Council to further minimize regulatory barriers to trade."

The obsession with immigration and border security in the current presidential campaign has at times even extended to Canada. But for the sake of the U.S. economy, making the line between the two countries less bright is the soundest path to growth.

Allowing energy markets to flourish is also on the list. The Obama administration irked Canadian authorities by derailing the Keystone XL pipeline, which would bring petroleum from the Alberta oil sands to refineries on the Gulf Coast. Canada holds a key to U.S. energy security. The vast Canadian reserves, combined with the newly unlocked supplies from fracking in the United States, make a U.S./Canada energy partnership extremely potent. Policies to jointly encourage energy development and relief from export bans could permanently alter the politics of worldwide energy production.

Terrorism at home is an increasing concern of both countries. Intelligence cooperation should be expanded.

The countries should work together to counter the recruitment and indoctrination of home-grown terrorists. And it is vital they cooperate in vetting refugees from Syria and elsewhere in the Middle East.

Finally, Obama should seek to work with Trudeau to increase Canada’s commitment to fighting ISIS and other terror groups abroad.

While Trudeau has pledged Canada will "do its part" in combatting ISIS, he is still intent on withdrawing its warplanes from the region.

The two nations have always fought side by side in international conflicts.

A strong Canadian presence in this struggle is essential.

U.S. ties to Canada are strong, and should be made stronger. Trudeau’s visit should be seen as a start toward achieving that goal.

— The Detroit News,

Detroit, Mich.