What, pray tell, is the purpose of restricting the distribution of alcohol to individuals over the age of 21? If it be, as one might assume, to prevent our young adult population from engaging in irresponsible acts and behaviors, then perhaps we shouldn't even bother calling such individuals "adults" at all. If that be the case, then one might also wonder if these non-adults are fit to make other adult decisions, such as voting, driving, owning firearms, joining the military, buying pornography, getting tattoos, engaging in sexual activity, eating vegetables, or trading labor for wages. In any case, the line must be arbitrary and the real distinction can only be whether or not an individual has reached a the proper level of physical, mental and emotional maturation needed to make an informed decision regarding engaging in such behavior, as well as having the capacity to bear the responsibilities involved with doing so. Contrast that with a consideration of where government derives its power and a logical analysis of where and how that power can realistically be applied both legitimately and effectively. The answer of course is that the law must strike a balance between preserving liberty and providing security, i.e., the people must decide which behaviors and rights that might endanger people are acceptable for the preservation of freedom. But when we look at this analysis in terms of real-world consequences, it is certainly evident that adults over the age of 21 have committed tragic mistakes and some engaging habitually self-destructive behaviors while under the influence of alcohol. Meanwhile, we can also observe that in areas that don't enforce the same restrictions, individuals under the age of 21 can be found to use alcohol responsibly. Ultimately, I think the laws here in the US have been enacted as a means of stimulating an environment of productivity. That is to say, the government sees young sobriety as in investment in the future, believing, be it cogent or fallacious, that a sober young population will achieve a higher level of achievement that makes the nation stronger as a result.