The change in rhetoric obviously isn't an end to the federal prohibition on drugs. But it isn't mere symbolism, either. Rhetoric matters.
The drug war imagery started by Nixon, subdued by Carter, then ratcheted up again in the Reagan administration (and remaining basically level since) has had significant repercussions on the way drug policy is enforced, from policymakers on down to street-level cops. It's war rhetoric that gave us the Pentagon giveaway program, where millions of pieces of surplus military equipment (such as tanks) have been transferred to local police departments. War imagery set the stage for the approximately 1,200 percent rise in the use of SWAT teams since the early 1980s, and has fostered the militaristic, "us vs. them" mentality too prevalent in too many police departments today.
War implies a threat so existential, so dire to our way of life, that we citizens should be ready to sign over some of our basic rights, be expected to make significant sacrifices, and endure collateral damage in order to defeat it. Preventing people from getting high has never represented that sort of threat.
No, a mere change in rhetoric isn't going to undo all of that. But it will at least begin to establish a less bellicose, less aggressive mindset when it comes to formulating drug policy. And while Kerlikowske's public health approach to drug enforcement is still a far cry from a government that respects individual freedom, it's also far better than the attitudes of his predecessors. We could, for example, go back to the days of William Bennett, who thought we should suspend habeas corpus for accused drug dealers, then took a sympathetic view when a caller to Larry King Live suggested we just behead them in the street.
Seems to me it's a positive and not insignificant development that we have a drug czar who understands the power of language.