Actually, soldier is an appropriate term. Many who have gone through a promotion board know that the correct GENERIC term for a member of the military, regardless of branch, is “soldier.”
It denotes a paid member of the military and is derived from an old english term for “pay.”
How many years of service do you have?
Oops.
Actually, it is not an appropriate term to use when one refers to Marines, xzins.
Marine is the first, middle, and last name.
You may technically be correct but in the real world, Marines should never be called soldiers any more than soldiers should be called sailors or Democrats called Americans.