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.
If you all agree to refuse to fight, you win.
https://en.wikipedia.org/wiki/Prisoner%27s_dilemma
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.