The answer to that is really that we're a part of the information network, so when a missile launch is detected through NORAD and through the Canadian connection to NORAD, that information is passed to government. It's not the Canadian Forces' responsibility to activate those civilian measures; it's actually Public Safety Canada's, but the Canadian Forces would then activate a potential response because our responsibility is to mitigate the potential attack.
On March 1st, 2018. See this statement in context.