Is it safe for a fourteen year-old to drive, so long as he wears a seat belt? Of course not... He should be more mature before his driving is considered safe, whether he is 'protected' or he is not. The same is true with regard to premarital sex for the teen-ager. He shouldn't be told 'if you are going to have sex, do it safely by using 'protection.' For the fourteen year-old, 'safe' sex isn't necessarily so. Only abstinence is.
If parents want more teen-agers to have 'protected' sex, the handing out of condoms and the assurance of increased safety is the way to go. If, on the other hand, a better parental objective is to get fewer (not more) fourteen year-olds to engage in sexual intercourse ('protected' or otherwise), the worst thing that those parents can do is convince the teen-agers that premarital sex is 'safe.' Parents shouldn't be giving teens the means to engage in sex while assuring them that the dangers are eliminated or even significantly reduced!
Protected or otherwise, unmarried teen sex is unwise and risky. It cannot be made 'smart' by using a condom. Premarital sex, just like adulterous sex, is wrong. For unmarried teen-agers, 'protected' sex is not safe...
Only abstinence is.