OTTAWA—The Trudeau government and Opposition Conservatives marked International Women’s Day on Monday by trading barbs and accusations over reported threats against a senior naval officer who brought forward an allegation of misconduct against Canada’s defence chief. The bitter back-and-forth came as members of the House of Commons defence committee agreed to invite a bevy of new witnesses to testify in an expanded probe of the Liberals’ handling of allegations against the military’s top brass. The list of new witnesses includes top Liberal officials as well as two former aides in the previous Conservative government. It also includes Lt.-Cmdr. Raymond Trotter, who reportedly flagged an allegation of misconduct by chief of the defence staff Admiral Art McDonald last month. Global News has reported Trotter subsequently received two threatening phone calls from blocked numbers, one from a person claiming to be a military officer and the other from someone who identified themselves …