No, I can't think of a single enemy we've been defended against by the US.Canada has always benefited from protection of the US
Most of the time yes, but the US reacts against any free countries that don't contribute to it's many wars of aggression.But they have also provided forces in global conflicts around the world
Blackmailed into taking part in your country's wars but the world is changing and other options may be considered in the future. Thank the dog that we chose right on Iraq.They are a responsible and dependable ally.