Bad idea. One volunteer is preferred to three ‘pressed men.
1) Bring down the quality of the military, because -- as you say -- volunteers tend to be better quality than people who'd rather not be there.
2) Bring down the political acceptability of war. If the soldiers are not there by choice than neither the voters nor the politicians will be eager to put them in harm's way.
If you want the country weak, bring back the draft. That's what this is about.
Draftees fought WWII, Vietnam was mostly volunteers, and draftees make fine soldiers, superior to females.
It is easier for drill sergeants to turn 18 year old draftees into warriors and change their minds about the challenges and fun of soldiering, than to change the realities of the limitations of the female sex.
This isn’t about a draft anyway, it is about national service.
“One volunteer is preferred to three pressed men.”
Considering the complexity of modern war machines, the ratio is likely even higher in many military specialties.