Another brick in the wall

Charles Krauthammer's discussion of the need for border security in today's WaPo raises a question I've wrestled with -- why not build a wall between the U.S. and Mexico? If the concern is merely one of symbolism, it's time to get over it. Walls have been used for millenia to control territory. They are practical, functional objects. Only when they are used to imprison people, to keep them in, a la the Berlin Wall, should they be considered objects of oppression. A wall to aid in border control seems to be one pillar of a humane, long-term immigration policy providing for control of the borders, a path to legalization for immigrants already settled in the U.S., and increased opportunities for legal immigration (i.e., a responsible increase in the ridiculously small numbers of visas available each year.).