As it stands, Canada can detect and release warnings about ballistic missile attacks on North America, but has left it to the U.S. to defend North America against such threats through its ground-based defence system that can shoot down these missiles, explained Andrea Charron, director of the Centre for Defence and Security Studies at the University of Manitoba. 

To Charron, it makes sense to revisit such questions at a time when rapidly advancing technology is pushing allies like the U.S. and NATO countries to look at how to make sure their air defence systems are able to protect people and their militaries against modern threats.