Man, I keep saying that I’m glad I have 3 daughters and (so far) no sons.
Wait until they get older and start dating. :eek:
-XT
Except that (except for in Paraguay) losing a large fraction of men in a given age cohort does not lead to polygyny, it leads to a generation of spinsters and the women who do find husbands picking up the slack. The biological impact on the population of a woman failing to breed is exactly the same as the impact of her dying in a war.
It doesn’t always lead to polygyny. Sometimes it does. Sometimes the surviving males just pump, dump and get with someone else afterwards. But that’s not a happy ending for the womenfolk either. However, at least the womenfolk survived… which is more than we can say for those men who die in wars.
That’s largely because social mores have changed, due to it having become so rare for so many men to die.
In Virginia, the driver’s license application had a box you could check (and if you were a male between 18 and 26, you HAD to check a box) to allow Virginia to use the information on your driver’s license application to register you for Selective Service. The other options were a declaration that you were already registered, and I think there was one where you could declare that you were exempt.
I’m not so sure that has to do with the rarity of men dying in such large numbers; it may have more to do with the arrival of birth control and women’s changing attitudes toward child bearing in general. I believe there are plenty of men in Japan but their birth rate is quite low; the same in Germany. There are lots of women there (and other places, too) who simply do not choose to have kids.
When war comes do we send women to war who choose not to have kids? 
If drafted soldiers are akin to slaves or prisoners, then I don’t see why female soldiers wouldn’t be treated similarly to female prisoners who give birth (shackled to a bed while giving birth and separated almost instantly from the newborn wiht the child going into foster care or to a relative). It would stress the system, but then I can’t imagine a scenario that wouldn’t.
Prisoners actually had to do something wrong. Slaves are more like it - with conscription, men have no choice. Serve or go to prison.
What about jury duty? Or compulsory education?
Then that country will fade and their enemies will ascend.