how a biological can be done by simply using a common passenger airplane:
older type passengerairplanes had toilets onboard that all contents went into kinda septic tank for storage.
before landing the pilots could empty the stuff.
now simply replace the dung of these septic tanks by a biological weapon liquid !
on the very early hours above the usa flies a civilian passengerplane from a small air line somewhere based in XYZ.
at a certain height flying just above in the warm,moist and damp morning haze the passengerplanes tanks are set to SPRAY and activated.
the concentration of the liquid falling down expands
the volume enormously,due to the ideal situation created by the weatherconditions.
shortly after this event pandemonum starts to happen...
people drop on the pavements,cars are driving straight into obstacles because the driver is motionless leaning aside,trains collide head on due to
both trainconductors passed away...
and to the pentagon people in charge.
once you have captured your enemy...
it is a tactical error to release them and give them
a new oportunty to return against you once more !