mostly special ops people do all those classified missions with extra high risks, you sign up for that and know the risks when you get in there but generally, if you follow orders and do what you're told you'll be okay...the risks are lined out to them before they go on a mission like that but those people are usually gung-ho and don't turn down missions like that but in general...no, they can't put just the average soldier on a high risk mission...besides, if death is "guarunteed" you won't be doing whatever "it" happens to be