Free trade isn't necessarily the best way to handle trade.  It's simply a matter of free trade being better than the other ideas we have so far.  Krugman once pointed out, in one of his books, that even if we were capable of developing a system that would work better, it would be a pointless exercise, because it would be too difficult to build in the real world.  A great deal changes, obviously, when politicians get involved.

Conservatives want live babies so they can raise them to be dead soldiers. - George Carlin