OTTAWA — Former foreign affairs minister Marc Garneau says Canada should push for a role in a new security pact, arguing South Korea and Ottawa could help each other gain strategic influence in the Indo-Pacific. "At a time when the geopolitical dialogue tends to be dominated by the superpowers, successful middle powers like Korea and Canada have things to say that are worth listening to," Garneau said in an interview. "There's the potential for us to work together and to, in a co-ordinated manner, have a greater voice on the world stage." Garneau is to be appointed next month as…