John Packer is the Neuberger-Jesin Professor of International Conflict Resolution at the University of Ottawa. This week, Canadians awoke to the idea – and possibly the fact – that one or more foreign agents murdered one of our neighbours in broad daylight … then slipped away. Prime Minister Justin Trudeau took our breath away when he informed the nation that there are “credible allegations of a potential link” with the June killing in Surrey, B.C., of Hardeep Singh Nijjar, a devoted Sikh nationalist, and agents of the Indian state. If true (as our government surely believes), such a political assassination…