EDMONTON—With NATO breathing down its neck, the Government of Canada has clammed up on what it will say about the Treaty on the Prohibition of Nuclear Weapons, which enters into force Jan. 22. The treaty, signed by 122 nations in 2017, is a breakthrough because it bans the possession of nuclear weapons for those states adhering to it. UN Secretary-General Antonio Guterres hailed the treaty as “historic,” adding that it will “form an important component of the nuclear disarmament and non- proliferation regime” and set a new global norm against nuclear weapons.