Even worse, they've started using some kind of biological warfare against us.

A guide to the science and history of biological warfare.

But it is in the 20th century that biological warfare became an industry.

"These were clearly agents that could be used for biological warfare."

But no such considerations stood in the way of biological warfare.

And were the aliens designed as a form of biological warfare?

But it is important to keep the risk of chemical or biological warfare in perspective.

This is used for protection against nuclear, biological and chemical warfare.

There is also a short history of American involvement with biological and chemical warfare.

This is biological warfare and we are on the side of the trees.

But nothing to do with germ warfare or anything dangerous.

Is that how you knew this had nothing to do with germ warfare?

That science in turn creates the possibility of germ warfare.

Mr. Green does know a thing or two about germ warfare, though.

What about, I don't know, some kind of germ warfare?

Some analysts call it the first modern case of germ warfare.

And the germ warfare that people have worried about for so long is under way.

But research for germ warfare cannot and should not be tolerated.

But scientists and Government officials have evidence that the dangers of germ warfare are growing.

And doctors are not trained to recognize the symptoms of germ warfare.