Prime Minister Mark Carney’s review of Canada's purchase of F-35 jets is another battle line drawn in the ongoing trade war. But it has also re-opened old scars. Canada has been trying to replace its aging jets for decades now. Two people who have lived the file, former defence minister Peter MacKay and former assistant parliamentary budget officer Sahir Khan talk to host Amanda Lang about the politics of procurement, the need for better discourse and what’s at stake.