If unattended, they would eventually die of a long miserable death. Unless the enemy is N. Korea or some other country who don’t care about human suffering. In which case, they would just be human shields.
My brother-in-law was in Korea when the Chinese invaded. The Chinese had so many excess people they thought nothing of throwing massive waves of Chinese against the American lines.
The first wave had rifles. The second had what ever they could find, spears, rocks, unarmed ones expected to pick up rifles from those ahead who had just been shot.
There is a scene in ZULU DAWN which reflects this. As you look down on the battle the Zulus keep running toward the British line. Those in front fall, those behind keep coming, and gaining ground till they roll over the British forces.