lower the drinking age nationally to 18 years old

Why is it that at 18 years of age you are able to go off to war and fight for your country, vote, buy tobacco, be tried as a an adult for a crime but you cannot buy an alcohol? I think it is only fair since at 18 you become a legal adult that you have the responsibilities and access to adult things such as alcohol. Why are we creating two different phases of adulthood instead of one when you turn 18? I think that we need to lower the drinking age to 18 so that we get rid of the forbidden fruit mentality surround alcohol because if access to it is easier then it won't be such a rush for kids and young adults to drink. Instead it will turn into a responsible social activity where the goal is not getting drunk, but instead is having a social event where you and your friends can get together.