Don't fret. It may suprise you to know that there are many of us wearing the uniform who fully expect your "hypothetical situation" to come true sooner rather than later. None of us want a terrorist strike on Canada - indeed, the opposite is true for anyone wearing the uniform or our nation. We work every day and put our lives on the line in far-flung places precisely to prevent such an occurence. But we are also realists and we therefore know (without question) that barring a fundamental change of world events, such an incident in Canada is all but inevitable.
The problem is that even if ((name your diety here) forbid) such an event should occur, the Canadaian government and general populace would be so far behind the power-curve in terms of sorting ourselves out that our immediate response would be entirely inadequate and meaningless. The thing about combatting terrorism is that you have to PRE-EMPT the terrorists - ideally through a combination of "good works" overseas and by killing those who presume to challenge our way of life. That's it - that's all there is too it. Unfortunately, those things are far easier said than done.
I'm with you - I think that Canada is primed for a big terrorist hit, and it is going to happen. And then what? A bunch of self-reflective hand-wringing combined with navel-gazing and self-serving "K'um Ba Ya" candlight vigils and a renewed pledge to be friends to the world? Or will we finally "get it" as a mollycoddled citizenry and promptly sort ourselves out as a nation - recognizing an immediate threat to our well-being and that of our children? Just as we have done in two world wars and several overseas combat actions during the earlier years of this century?
The fact is that Canada has grown too soft for its own good. Our collective conscience has been overtaken by rampant and unwarranted political correctness, coupled with a misplaced utopian belief that we can "get by" without overtly offending anyone. Unfortunately, that Canadian societal premise is fundamentally flawed, and has been from the outset. We are already at war, and we chose our side/made our bed when we sent 3 PPCLI on combat operations against the Al Quaida and Taliban in Afghanistan 3 years ago. There is no turning back, unless we collectively choose to turn belly-up and have our women don Burkhas. Because that is the choice. There is no middle ground to be negotiated with those who would purport to impose their radical religious beliefs upon us. We fight, or we die. Simple eh? Sadly, most Canadians cannot yet comprehend the fundamental reality of the situation. We are at WAR. Full-stop.
Getting back to your point, we all know that you don't want a terrorist strike against Canada resulting in mass casualties in one of our urban centres. None of us does. Heck - I've been wearing the uniform for 25 years in an active personal attempt to prevent just that. But the fact remains that if we don't get our collective societal crap together, that is precisely what is going to happen. You know it, and I know it. And I'm sorry to have to agree with you that such an event is likely the only thing that will awaken the navel-gazing, self-indulgent and falsely secure Canadian public from their collective slumber. I sincerely rue the day, but I have zero doubt that it is coming. And sooner rather than later.
All of the above to say that your concerns are fully warranted, and you are not off-base. It is only a matter of time, and the "grown-ups" know it - even if they are not yet admitting it.
See you when the dust settles.