If underage drinking were legal in the US, as it is in other places, it would be much less abused than it is now. Half the time children and teens take up drinking just because it is a risky activity, and they do it outside of adult supervision because they know it isn't allowed. If underage drinking were allowed, parents would be able to monitor it, it would lose its 'bad' draw, and it would pose much less of a problem.
When the underage drink, they jack up their brain cells, cause violence, hostility, and cause them to express their feelings in a violent way. Those that can drive often cause crashes and kill or injure innocent bystanders. It can cause depression and hostility. So yeah. Underage drinking should be very illegal. Plus... IT ALREDY IS!!!!
Underage drinking should be illegal. When teenagers and other underage drink, they are only messing up their brain before it is done developing. The drinking age is so high for a reason- if it were any lower, then children's brains would be messed up from all the alcohol that they consume.