Easier to repopulate... at the expense of men being considered essentially disposable by the society. I should have as much right to not being forcefully sent to my death to wage billionaires' wars as the other half of population.
Well, you see, if men stay alive, but women are killed, society collapses eventually as not enough new people are born. It sucks being a man in this scenario, but it is what it is.
And if you include women (well, all genders) directly in the war efforts you double the amount of soldiers you have, which would increase your chance of winning and not needing to repopulate.
The key here is to refuse fighting. Nobody becomes a hero by becoming a murderer whose goal is to defend the political power of Stalin, Napoleon, Bush, or whoever.
I suspect one tool governments across the world will resort to when they get desperate about sub-replacement fertility is changing mandatory conscription from males to the childless. Quite strong incentive, not be sent to the meatgrinder.
