TORONTO — The move by the federal government to force Chinese companies to sell their investments in three critical mineral companies is being called a meaningful and necessary escalation of Canada's defensive posturing on strategic assets. The order Wednesday from Innovation Minister François-Philippe Champagne, which followed an announcement last week that he would be limiting foreign state-owned companies in the industry, shows the government is responding to a changing world, said Aaron Shull, managing director at the Centre for International Governance Innovation. "They're on their front foot now," said Shull. The decision to force Chinese divestment of critical mineral companies…