Drug prohibition, a global policy based on pseudoscience and wishful
thinking, has an unbroken record of futility.

Pursuing it has also become an irresponsible bureaucratic goal,
especially in the US.

Kurt Kleiner's account of US attempts to deploy a "bioweapon"
against the coca bush (11 March, p 5) provides a good example.

It suggests how careless implementation of "anti-drug" policy can
injure the environment. The fungus they propose using has an
incompletely known avidity for flora besides the coca bush. Kleiner's
carefully neutral article neglects another, equally important facet of
drug war futility. Even if the wildest dreams of government plant
pathologists were to be realised---coca precisely nudged into
extinction without damage to other plants---the most predictable
result would simply be a huge boost for the already robust black
market in methamphetamine, cocaine's substitute of choice, which, when
synthesised by criminals, is an environmental nightmare in its own
right.

Tom O'Connell
San Mateo, California