This Sunday in Toronto, thousands of people are scheduled to take part in a walk to demonstrate support for the people of Israel and raise money for those who have suffered from the Oct. 7 terror attack. The mayor, Olivia Chow, should walk alongside them. Canada’s Jewish community is feeling beleaguered, isolated and fearful. A series of attacks on Jewish institutions has undermined its sense of security and shaken its faith in the ability of the authorities to keep it safe. Just in the past couple of weeks, two Jewish schools have been hit by gunfire. A Vancouver synagogue suffered...