In my opinion the ages for drinking/smoking should not be raised to 21. While I am not a fan of either and they almost never lead to good things, it just seems odd to me that a person can fight for his country at 18, but can't smoke or drink.
Yes, because most teenagers or early adults make bad choices. They should raise the age so when they are actual adults they can hopefully make the right decision.
Try looking on this website is you don't believe in my opinion. http://www.debate.org/opinions/should-the-smoking-age-be-raised-to-21