I'd welcome it personally. The only reason I havent joined the army yet is because i havent found a cause worth fighting for (all the countries currently fighting each other in the middle east can blow each other up for all I care). So if we were being drafted, then it means there is either another big world war type of war or my country was being attacked. Either way I'd love to join up, I dont see a reason why I'd be a draft dodger unless it was because of some sort of civil war against the government, in which case there would be a whole bunch of variables as to what I would do, depending on the situation.
But yeah, if Canada found ourselves in world war 3 I'll be the first in the line up to join up. Of course, there are different variables as to what my choice would be, but if I felt there was a threat to my existence then yes I would join up in a new york minute and give it 150% effort.
On a side note, knowing my luck I'd probably be one of those guys all excited when we're getting deployed into battle and be all like "all right guys, lets do this!" then run out and get my head blown off in 2 seconds in the front wave, even though I would like to think I would survive longer than that.