Shares of defense prime contractor Lockheed Martin have been under siege amid changes in U.S. leadership and questions about the viability of technologies it produces.Now, Canada is questioning its purchase of Lockheed’s F-35 jet fighters,

Canada, locked in a trade war with the United States, is reviewing a C$19-billion ($13.29 billion) contract for 88 American-made F-35 fighter jets from Lockheed Martin but switching planes could be costly and complex,