If the weapon (silica, polymerized glass and all) came from a US lab then it had to have been a sanctioned operation. There is no way such a weapon could be removed from a secure lab with double-keyed doors (ie. at least 2 different parties from different divisions performing the opening), 24 hour video surveillance and with samples kept in bonded containers,without permission. That's how tight security is on BW's - that is, if a new weapon was illegaly made inisde the US in the first place.
So we have 2 choices - both bad. The first choice is that the US government murdered her own citizens and attempted to murder elected members of congress in order to set up a pretext for war with Iraq.
The second choice is that a foreign government attacked the US with bioweapons and the US government is covering that up.
Or 3, they just don't know (not helped by some distracting wild goose chases.)
I think there's other possibilities for motives, eg the second wave theory, personal, etc.
It's always struck me as interesting the first targets selected. Major broadcast network anchormen, NYPost and J.Lo or AMI. Not CNN, NYTimes, etc. Might indicate the level of media attention the perp/s have.
That's why I've always said what was key is J.Lo. Even if a different letter with AMI as the first addressee was the weapon, why target a tabloid almost and also not name a major news figure?