It's every country's responsibility to look out for its own best interests
Canada does it. So does every other country unless they're very foolish. The best situation is when a country's best interests are also beneficial to others. It so happens that promoting freedom abroad is not only in our interests, it's in the interest of people everywhere except for those who wish to subjugate others through tyranny. If we help others be free, who is harmed? By the same token, who can we count on to help preserve our security and prosperity if we aren't willing to do so ourselves? The UN? Canada? Europe? Sorry, no. Someone has to be the adults, make the hard decisions, and pay the price.