US charges Pakistan Taliban leader

The US criminal complaint against Tehreek-e-Taliban Pakistan leader Hakimullah Mahsud, can be found here. The document, unsealed last week, makes interesting reading, although it still does not explain how so many CIA officers were killed and wounded by suicide bomber Humam Khalil Abu Mulal al-Balawi, the Jordanian doctor who penetrated the US military base in Khost on 30 December last year.
Drawn up by FBI special agent Thomas Q Krall on 20 August, it states that "witnesses advised that at approximately 4.30pm local time al-Balawi arrived at the base by car. He exited the rights side of the vehicle and appeared to be wearing traditional Afghan attire. He was also carrying a crutch or cane. Base security approached al-Balawi as he stood next to the vehicle. Al-Balawi was observed reaching under his clothing and then detonating an explosive device that was hidden under his clothing. The blast from the explosion killed al-Balawi and seven US citizens. It also injured six other US citizens."
Other accounts of the incident suggest that al-Balawi was in a room crowded with CIA personnel when he detonated his bomb. He had not been searched and this was why his attack was so devastating. This seems to make more sense than the scenario of him exploding his bomb when approached by security staff, as set out in Krall's affidavit.
Hakimullah is charged with conspiracy to murder US nationals outside the United States and also with conspiring to use a weapon of mass destruction. In US law, a weapon of mass destruction is defined to include any "destructive device", including a bomb, grenade, rocket with more than four ounces of propellant, a mine or a missile having an explosive on incendiary charge of more than a quarter of one ounce. Under this definition, just about everything bar a bullet is a "weapon of mass destruction". In fact the definition is so wide as to be meaningless. Did this definition also apply to Saddam's Iraq, I wonder?