If you want to prepare and carry out a biologcal attack, the last place you would do it from is the other side of the planet. You'd do it from inside the country you wanted to attack. And you wouldn't need to have some foreign government telling you what to do, any more than the boxcutter hijackers needed that on September 11th.

I cannot really imagine how blowing up buildings and killing people in Iraq is going to do anything whatsoever to reduce the possibility of a biological attack on the USA or the UK. I can imagine how it might have the reverse effect.

I remember a science-fiction story about biological war, I think by Arthur C Clarke (though I'm not sure about that). The twist was that it was defensive. The whole population of a country under imminent danger of attack was "immunised" in such a way that it made them carriers of a lethal disease that they couldn't catch. Any invaders would catch it and die. (Mind it must really have buggered up the tourist industry.)