If you sign up to kill people, and it’s not in reaction to an attack on your country, you are by definition just a mercenary. I don’t wish death on you, but I don’t feel much when you die and I don’t think you deserve any special consideration by society for your questionable career choice.
A person paid by a government to follow orders and enact violence upon a target or targets chosen by the authorities in that government… Am I describing a member of the military or a contractor for a PMC like Academi? It’s a legal distinction without a functional difference, like a corporation vs an LLC. There are limited circumstances where, in a court, they are treated differently but the product that comes from them and the processes by which it is produced are essentially the same.