Its not the job of soldiers to give their lives, only to risk their lives. In your question, there is a certainty of outcome that doesn't exist for soldiers and there fore makes the question the wrong one. Unless an option of "I would risk my life." instead of "I would give my life" is up there, then it isn't really a fair question.
I understand what you are saying. And to an extent I agree. However, two thoughts made me change my mind on that wording.
1) Soldiers have already died. So it is not a "what if" statement.
2) If a soldier is not willing to die, he probably isn't a going to do a good job. I would not want to fight in a war I believed in with other guys that didn't believe in the cause.