How might the Columbian Exchange be considered a bio-terrorist attack?

An interesting idea; as smallpox, etc. devastated native
American populations, sometimes wiping out entire cultures. Jared Diamond makes this
point quite well in Guns, Germs and Steel. One of the more ironic
elements is that large numbers of people died who never came into contact with
Europeans; the diseases were that pervasive.

A problem with
considering the entire exchange as biological warfare is that by and large, Europeans
did not intend to use germ warfare to
destroy these people; it was an incidental and to a large extent unintended consequence.
One should also consider the fact that the Indians returned the favor: syphilis was
unknown in Europe until European sailors and explorers intermingled with the Indians;
yet again, however, this was an incidental and unintended consequence. That being the
case, I'm not sure "biological terrorism" is the proper
term.

There was at least one incident in which germ warfare
is unquestionably the term: settlers at Jamestown gave Indians blankets which they knew
to be infected with smallpox in a deliberate attempt to spread the disease. Other than
this one incident (when the poison they otherwise would have used wasn't available) I'm
not sure the entire exchange qualifies.