The Chinese-owned company which owns Darwin port has launched international legal action to try and stop the federal government from stripping it of the strategically sensitive asset.It says the government's move is "discriminatory" and breaks Australia's obligations under its free trade pact with Beijing.Anthony Albanese pledged at the federal election that Labor would return the port to Australian hands, saying it was necessary for national security.The government has since been locked in negotiations with Landbridge as it tries to secure an Australian buyer and has flagged that it is willing to force the company to hand over the port if…