Could ? No they cant. Even though they could theoretically. Practically no. Because they could not handle the shitstorm following his arrest. USA is still the most powerful country and they would see that clearly as challenging their authority. The US would smack their whole economic weight into canadas face. International law ? In the end countries do what they want if they have the power.
Canada knows that they wouldnt be able to arrest him unless USA allows it. How exactly should that work ? Worst case scenario the US would send a commando into canada and take him back with violence just to show the world that nobody should dare to arrest a former US president even a "friend".
There are things that you cant do. You think China or Russia would allow Ukraine/North Korea to arrest former president leaders ? This is like a declaration of war. USA might be democratic but this arrest would be a sign of weakness.
Canadas leader know that and would never arrest him NEVER. They dont have the Power to do it. Nobody has. How exactly could that work ? If USA doesnt say its fine. They invade countries if they think their interests are in danger (not officialy ofcourse).







