Who’s the most powerful conservative leader in the Americas, north and south? That may sound like a trick question, but it’s not. The answer is Stephen Harper, the Canadian prime minister who triumphed last week in an election that all but destroyed two opposition parties, the Liberals and the Bloc Québécois (BQ)….

Relations with the United States were not a major issue in the campaign. There was no U.S.-bashing, even from the left-of-center NDP and Green party. But dealing with the Obama administration is a top item on Harper’s agenda.

Since he became Conservative party leader in 2004, Harper, 52, “has practiced [former Conservative Prime Minister] Brian Mulroney’s golden rule for the conduct of relations with the U.S.—we can disagree without being disagreeable,” wrote Colin Robertson, vice president of the Canadian Defence and Foreign Affairs Institute. “Now he needs to follow the second Mulroney dictum—Canada’s influence in the world is measured by the extent to which we are perceived as having real influence in Washington.”

Harper has succeeded in building a solid relationship with President Obama. He never criticizes the administration, at least publicly. Now he needs Obama’s cooperation on two issues.

When Harper visited the White House in February, he and Obama announced the Declaration on a Shared Vision for Perimeter Security and Economic Competitiveness, an idea first broached, post-9/11, by President Bush. It would require a new agreement to ease travel restrictions between the United States and Canada, but is yet to be implemented. Also, economic regulations need to be harmonized.

The second issue is a proposed pipeline, the Keystone XL, to carry oil from northern Alberta to the Gulf Coast of Texas. The United States imports twice as much oil from Canada as it does from Saudi Arabia and Mexico combined, and the Keystone XL pipeline would allow us to rely even more on Canada, a friendly and nearby ally.

The problem, however, is that some environmentalists claim this is “dirty oil,” which contributes far more than other oil to global warming. It’s not true, but the argument has support in the Obama administration’s outpost of environmental extremism, the Environmental Protection Agency.

Because the pipeline would cross the Canadian-U.S. border, it must be approved by the State Department. Secretary of State Hillary Clinton seems willing to sign off, but the president also needs to be on board. Harper delivered a personal appeal to Obama at their February meeting and made the case for the pipeline at their joint press conference. The president was silent on the matter. Rejection of the pipeline would be a devastating blow to Harper, his party, and Canada….

Fred Barnes is executive editor of The Weekly Standard.