EDMONTON — Former U.S. president Bill Clinton thanked Canadians for staying the course in Afghanistan, knowing the price of that commitment is the blood of its soldiers.

"It's painful that you're losing people there and I'm sorry," Clinton said Thursday in a speech to 7,000 people at Rexall Place.

"But you've done a good thing for the cause of freedom and the stability of Canada.

"And as a citizen I am profoundly grateful that you've stayed the course and I appreciate it," he said to applause.

The 59-year-old Clinton said in an increasingly interdependent world, keeping order in Afghanistan reaches beyond its borders.

He noted that should troops pull out, the government of President Hamid Karzai, a moderate Muslim, would have to reach out to local drug warlords to keep control.

"If we were to abandon him, he would be forced to make even more deals with those people, which would bring more drugs to Canada, the United States and Europe," he said.

Political chaos, he said, would also re-open the door to Taliban forces to retake control of parts of the country and give terrorist groups such as al-Qaida a staging ground for attacks abroad.

Prime Minister Stephen Harper said last week that Canada will continue its support for the military mission in Afghanistan. He made the declaration as a public opinion poll suggested more than 60 per cent of Canadians questioned the country's role there.

Canadian troops have been attacked on a regular basis. Several have been hurt or killed by roadside bombs, rocket-propelled grenades and explosions by suicide bombers.

Clinton criticized religious extremism and the terror that it can spawn.

"If you think you can kill somebody else in the name of God it must mean that you believe you have absolute possession of God's truth and that you have turned it into a political program, which is absolutely true.

"And therefore (if) someone rejects the absolute truth, well, they're less than human anyway and who cares if they die and their kids die with them."

On Canada-U.S. trade relations, he said that despite concerns over softwood lumber and wheat under the North American Free Trade Agreement, the system is working.

"It's inconceivable that as complicated as our economic relationship is that we could integrate all these systems without somebody having a fight about something."

NAFTA will work, he said, because it has to.

"We're stuck with each other. We can't get a divorce. And that is the ultimate definition of interdependence - we're tied together, rowing in this little boat toward tomorrow."

Clinton's wife, Hillary Rodham Clinton, a junior U.S. senator from New York, is being touted as a possible future presidential contender.

He said she would do an outstanding job but pointed to recent surveys and wondered if his country was ready for a female chief executive.

"In general there's still a tilt to a male preference at executive positions, but they're willing to suspend it if they believe the woman in question is strong enough.

"And yet if women are really strong, then they're liable to drive men off the wall - that's been my observation over time," he said to laughter.

"My view is we ought to always vote for the person who would do the best job, and to take out more than half our population from consideration on the front end is really dumb."

Earlier Thursday, Clinton told an audience in Regina that people have the power to make a difference globally - and not just when disaster strikes.

"If you gave any money to the tsunami (relief effort), you were being a global citizen building an interdependent world, " he told a full house at the Conexus Arts Centre.

"As a citizen, you have more power to do that than ever before.

"I'm convinced if we truly see each other the way we now only do in a moment of common understanding over heartbreak, if we could do that on a daily basis, the 21st century will be far more peaceful and prosperous than the last one was."

Clinton has been speaking across Canada this week. He will be in Vancouver Friday.