Well not only that but it's a patently ridiculous scenario; if one thinks there is an imminent threat of being attacked on one's own soil by a power which would require conscription to defeat, kindly do explain what you believe said power to be.
I don't think it will happen, but such hypotheticals are irrelevent to the point itself.
Uh no, if you are advocating things based on obviously ridiculous hypotheticals you have to provide evidence that your hypotheticals are not, in fact, ridiculous. It's essentially the equivalent of claiming gay marriage will turn children gay. Not a valid argument unless you can provide evidence that the hypothetical has the potential of being real.