First we have to assess our enemies.
To the South, we have a friend (the USA). To the West, we have an ocean, with friends (Japan and South Korea, and increasingly China based on Harper's visit there recently). To the East, we have an ocean and more friends (the EU members, with whom we do have disagreements like with do with the US at times, but friends they are). To the North, we have tundra, another ocean, and more friends (Greenland, Sweden, Norway) and countries that are at worst benign (Russia).
Now we do have extremist terrorists, but it would seem teh RCMP would be in a better position to protect us against them than the military would, seeing that that fight is mostly at our airports.
So, pray tell, who is our big enemy who is planning on attacking us? North Korea? Even its ally China is tired of it and seems to have friendlier relations with South Korea. Iran? It values its trade agreement with China and China is not likely to let it start WWIII.
So who, pray tell?
Honestly, all Canada would really need would be some kind of international military force comprising a maximum 100,000 well trained and equipped men, funding for which could be shared between Canada and many countries.
But big-government statists could never suppport that because then how else could militarists create jobs in times of recession.
I say let the private sector create the jobs. Our military ought to be as big as we need it to be and no more.
Or are we expecting some intergalactic invasion I'm unaware of?