I get what you mean OP. A collective of aliens with superior technology and weaponry who are hellbent on exterminating humanity completely and have even destroyed entire planets to do so are simply not enough of a threat for conscription. Human's are recruiting like they are in peacetime with propaganda to fill the void. Hell this war should be more significant than any, humanity's survival depends on it. As Lord hood said [i]"We risk everything. Every last man, woman, and child."[/i] But yeah, "Human's have enough people in their armies, ONI has very good propaganda to how the war is portrayed to average citizens etc." This is simply one element of science-[u]fiction[/u] that gets overlooked. Edit- When you're facing such threat, you can never have too many people on your side. I think it's absurd to say that X is enough people to hold off a alien extermination whose numbers and technology outnumbers yours by so and so. Well in Halo, I guess X would be Master Chief. [Edited on 09.18.2012 2:48 PM PDT]