Great question, Kylemck. Although pain is a really horrible sensation, it’s an incredibly useful one to feel. For instance, if I couldn’t feel pain and accidentally caught my hand in a fire, I wouldn’t realise that I was burning myself. Even though the pain sensation wouldn’t be there, I’d still be doing a lot of damage to myself – I might not realise if the injury subsequently gets infected, or if that infection spread to other parts of my body. Likewise for a soldier, if they didn’t realise they’d been shot because they didn’t feel it hurt, then they might bleed to death.
Pain is also a good signal in learning about danger, too. If you put your hand in a boiling pan of water, you retract it pretty quickly because of the pain. That helps you to learn next time to be more careful, and avoid doing the same thing. If you didn’t have that pain response, you might carry on repeating the same things that cause injury, and eventually might do something that results in death. In the same way, if a soldier didn’t feel pain, they might rush into situations that others would think of as being highly dangerous, and might get themselves killed in the process.
So to answer your question, I think it would be a really bad thing to remove the sensation of pain, not just for soldiers but for everybody!